TOP242PN-TL - Power Integrations, Inc.

Figure 1. Typical Flyback Application.

PRODUCT3Adapter1Open

Frame2Open

Frame2

OUTPUT POWER TABLE

Table 1. Notes: 1. Typical continuous power in a non-ventilated

enclosed adapter measured at 50 °C ambient. 2. Maximum practical

continuous power in an open frame design at 50 °C ambient. See

Key Applications for detailed conditions. 3. See Part Ordering

Information. 4. 230 VAC or 100/115 VAC with doubler.

PI-2632-060200

IN DC

OUT

TOPSwitch-GX

CONTROL

230 VAC ±15%4

Adapter1

85-265 VAC

9 W 15 W 6.5 W 10 W

21 W 22 W 11 W 14 W

10 W 22 W 7 W 14 W

13 W 25 W 9 W 15 W

29 W 45 W 17 W 23 W

20 W 45 W 15 W 30 W

16 W 30 W 11 W 20 W

34 W 50 W 20 W 28 W

30 W 65 W 20 W 45 W

37 W 57 W 23 W 33 W

40 W 85 W 26 W 60 W

40 W 64 W 26 W 38 W

60 W 125 W 40 W 90 W

42 W 70 W 28 W 43 W

85 W 165 W 55 W 125 W

43 W 75 W 30 W 48 W

105 W 205 W 70 W 155 W

44 W 79 W 31 W 53 W

120 W 250 W 80 W 180 W

45 W 82 W 32 W 55 W

135 W 290 W 90 W 210 W

Product Highlights

Lower System Cost, High Design Flexibility

•Extended power range to 290 W

•Features eliminate or reduce cost of external components

•Fully integrated soft-start for minimum stress/overshoot

•Externally programmable accurate current limit

•Wider duty cycle for more power, smaller input capacitor

•Separate line sense and current limit pins on Y/R/F packages

•Line under-voltage (UV) detection: no turn off glitches

•Line overvoltage (OV) shutdown extends line surge limit

•Line feed forward with maximum duty cycle (DCMAX)

reduction rejects line ripple and limits DCMAX at high line

•Frequency jittering reduces EMI and EMI filtering costs

•Regulates to zero load without dummy loading

•132 kHz frequency reduces transformer/power supply size

•Half frequency option in Y/R/F packages for video applications

•Hysteretic thermal shutdown for automatic fault recovery

•Large thermal hysteresis prevents PC board overheating

EcoSmart

Energy Efficient

•Extremely low consumption in remote off mode

(80 mW @ 110 VAC, 160 mW @ 230 VAC)

•Frequency lowered with load for high standby efficiency

•Allows shutdown/wake-up via LAN/input port

Description

TOPSwitch-GX uses the same proven topology as TOPSwitch,

cost effectively integrating the high voltage power MOSFET,

PWM control, fault protection and other control circuitry onto a

single CMOS chip. Many new functions are integrated to re-

duce system cost and improve design flexibility, performance

and energy efficiency.

Depending on package type, the TOPSwitch-GX family has

either 1 or 3 additional pins over the standard DRAIN, SOURCE

and CONTROL terminals allowing the following functions: line

sensing (OV/UV, line feedforward/DC max reduction), accu-

rate externally set current limit, remote on/off, and synchroni-

zation to an external lower frequency and frequency selection

(132 kHz/66 kHz).

All package types provide the following transparent features:

Soft-start, 132 kHz switching frequency (automatically reduced

at light load), frequency jittering for lower EMI, wider DCMAX,

hysteretic thermal shutdown and larger creepage packages. In

addition, all critical parameters (i.e. current limit, frequency,

PWM gain) have tighter temperature and absolute tolerance, to

simplify design and optimize system cost.

TOP242 P or G

TOP242 R

TOP242 Y or F

TOP243 P or G

TOP243 R

TOP243 Y or F

TOP244 P or G

TOP244 R

TOP244 Y or F

TOP245 R

TOP245 Y or F

TOP246 R

TOP246 Y or F

TOP247 R

TOP247 Y or F

TOP248 R

TOP248 Y or F

TOP249 R

TOP249 Y or F

TOP250 R

TOP250 Y or F

TOP242-250

TOPSwitch

Family

Extended Power, Design Flexible,

EcoSmart

, Integrated Off-line Switcher

September 2002

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Section List

Functional Block Diagram......................................................................................................................................... 3

Pin Functional Description........................................................................................................................................ 4

TOPSwitch-GX

Family Functional Description ........................................................................................................5

CONTROL (C) Pin Operation .................................................................................................................................6

Oscillator and Switching Frequency .......................................................................................................................6

Pulse Width Modulator and Maximum Duty Cycle .................................................................................................7

Light Load Frequency Reduction............................................................................................................................7

Error Amplifier.........................................................................................................................................................7

On-chip Current Limit with External Programmability.............................................................................................7

Line Under-Voltage Detection (UV) ........................................................................................................................8

Line Overvoltage Shutdown (OV)...........................................................................................................................8

Line Feed Forward with DCMAX Reduction ..............................................................................................................8

Remote ON/OFF and Synchronization...................................................................................................................9

Soft-Start ................................................................................................................................................................9

Shutdown/Auto-Restart ..........................................................................................................................................9

Hysteretic Over-Temperature Protection ................................................................................................................9

Bandgap Reference................................................................................................................................................9

High-Voltage Bias Current Source........................................................................................................................10

Using Feature Pins.................................................................................................................................................... 11

FREQUENCY (F) Pin Operation........................................................................................................................... 11

LINE-SENSE (L) Pin Operation............................................................................................................................ 11

EXTERNAL CURRENT LIMIT (X) Pin Operation ................................................................................................. 11

MULTI-FUNCTION (M) Pin Operation ..................................................................................................................12

Typical Uses of FREQUENCY (F) Pin ......................................................................................................................15

Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins.......................................................16

Typical Uses of MULTI-FUNCTION (M) Pin .............................................................................................................19

Application Examples...............................................................................................................................................21

A High Efficiency, 30 W, Universal Input Power Supply........................................................................................21

A High Efficiency, Enclosed, 70 W, Universal Adapter Supply..............................................................................22

A High Efficiency, 250 W, 250 - 380 VDC Input Power Supply.............................................................................23

Multiple Output, 60 W, 185 - 265 VAC Input Power Supply..................................................................................24

Processor Controlled Supply Turn On/Off ............................................................................................................25

Key Application Considerations ..............................................................................................................................27

TOPSwitch-II

vs.

TOPSwitch-GX..........................................................................................................................

TOPSwitch-FX vs. TOPSwitch-GX .......................................................................................................................

TOPSwitch-GX

Design Considerations ................................................................................................................29

TOPSwitch-GX

Layout Considerations.................................................................................................................31

Quick Design Checklist.........................................................................................................................................31

Design Tools .........................................................................................................................................................33

Product Specifications and Test Conditions ..........................................................................................................34

Typical Performance Characteristics ......................................................................................................................41

Part Ordering Information ........................................................................................................................................45

Package Outlines ......................................................................................................................................................45

TOP242-250

9/02

Figure 2a. Functional Block Diagram (Y, R or F Package).

PI-2641-061200

PI-2639-060600

Figure 2b. Functional Block Diagram (P or G Package).

PI-2631-061200

SHUTDOWN/

AUTO-RESTART

PWM

COMPARATOR

CLOCK

SAW

CONTROLLED

TURN-ON

GATE DRIVER

CURRENT LIMIT

COMPARATOR

INTERNAL UV

COMPARATOR

INTERNAL

SUPPLY

5.8 V

4.8 V

SOURCE (S)

DMAX

STOP SOFT-

START

CONTROL (C)

MULTI-

FUNCTION (M)

5.8 V

IFB

LEADING

EDGE

BLANKING

÷ 8

HYSTERETIC

THERMAL

SHUTDOWN

SHUNT REGULATOR/

ERROR AMPLIFIER

DRAIN (D)

ON/OFF

SOFT

START

DCMAX

VBG

DCMAX

VBG + VT

OV/UV

VI (LIMIT)

CURRENT

LIMIT

ADJUST

LINE

SENSE

SOFT START

LIGHT LOAD

FREQUENCY

REDUCTION

STOP LOGIC

OSCILLATOR WITH JITTER

PI-2639-060600

SHUTDOWN/

AUTO-RESTART

PWM

COMPARATOR

CLOCK

SAW

HALF

FREQ.

CONTROLLED

TURN-ON

GATE DRIVER

CURRENT LIMIT

COMPARATOR

INTERNAL UV

COMPARATOR

INTERNAL

SUPPLY

5.8 V

4.8 V

SOURCE (S)

DMAX

STOP SOFT-

START

CONTROL (C)

LINE-SENSE (L)

EXTERNAL

CURRENT LIMIT (X)

FREQUENCY (F)

5.8 V

1 V

IFB

LEADING

EDGE

BLANKING

÷ 8

HYSTERETIC

THERMAL

SHUTDOWN

SHUNT REGULATOR/

ERROR AMPLIFIER +

DRAIN (D)

ON/OFF

SOFT

START

DCMAX

VBG

DCMAX

VBG + VT

OV/UV

I (LIMIT)

CURRENT

LIMIT

ADJUST

LINE

SENSE

SOFT START

LIGHT LOAD

FREQUENCY

REDUCTION

STOP LOGIC

OSCILLATOR WITH JITTER

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Pin Functional Description

DRAIN (D) Pin:

High voltage power MOSFET drain output. The internal

start-up bias current is drawn from this pin through a switched

high-voltage current source. Internal current limit sense point

for drain current.

CONTROL (C) Pin:

Error amplifier and feedback current input pin for duty cycle

control. Internal shunt regulator connection to provide inter-

nal bias current during normal operation. It is also used as the

connection point for the supply bypass and auto-restart/

compensation capacitor.

LINE-SENSE (L) Pin: (Y, R or F package only)

Input pin for OV, UV, line feed forward with DCMAX reduction,

remote ON/OFF and synchronization. A connection to

SOURCE pin disables all functions on this pin.

EXTERNAL CURRENT LIMIT (X) Pin: (Y, R or F

package only)

Input pin for external current limit adjustment, remote

ON/OFF, and synchronization. A connection to SOURCE pin

disables all functions on this pin.

MULTI-FUNCTION (M) Pin: (P or G package only)

This pin combines the functions of the LINE-SENSE (L) and

EXTERNAL CURRENT LIMIT (X) pins of the Y package

into one pin. Input pin for OV, UV, line feed forward with

DCMAX reduction, external current limit adjustment, remote

ON/OFF and synchronization. A connection to SOURCE pin

disables all functions on this pin and makes TOPSwitch-GX

operate in simple three terminal mode (like TOPSwitch-II).

Figure 3. Pin Configuration (top view).

PI-2509-040501

Input

Voltage

VUV = IUV x RLS

VOV = IOV x RLS

For RLS = 2 MΩ

VUV = 100 VDC

VOV = 450 VDC

DCMAX@100 VDC = 78%

DCMAX@375 VDC = 38%

CONTROL

2 MΩ

PI-2517-040501

Input

Voltage

For RIL = 12 kΩ

ILIMIT = 69%

CONTROL

RIL

See fig. 55 for other

resistor values (RIL)

For RIL = 25 kΩ

ILIMIT = 43%

to select different

ILIMIT values

PI-2629-040501

Input

Voltage

CONTROL

RIL

RLS

12 kΩ

2 MΩ

VUV = IUV x RLS

VOV = IOV x RLS

For RLS = 2 MΩ

DCMAX@100 VDC = 78%

DCMAX@375 VDC = 38%

For RIL = 12 kΩ

ILIMIT = 69%

See fig. 55 for other

resistor values (RIL)

to select different ILIMIT

values

VUV = 100 VDC

VOV = 450 VDC

Figure 4. Y/R/F Package Line Sense and Externally Set Current

Limit.

Figure 5. P/G Package Line Sense.

Figure 6. P/G Package Externally Set Current Limit.

FREQUENCY (F) Pin: (Y, R or F package only)

Input pin for selecting switching frequency: 132 kHz if

connected to SOURCE pin and 66 kHz if connected to

CONTROL pin. The switching frequency is internally set for

fixed 132 kHz operation in P and G packages.

SOURCE (S) Pin:

Output MOSFET source connection for high voltage power

return. Primary side control circuit common and reference point.

PI-2724-010802

Tab Internally

Connected to

SOURCE Pin

Y Package (TO-220-7C)

1 C

3 X

2 L

5 F

4 S

7 D

P Package (DIP-8B)

G Package (SMD-8B)

R Package (TO-263-7C)

F Package (TO-262-7C)

12345 7

CLXSF D

TOP242-250

9/02

TOPSwitch-GX

Family Functional Description

Like TOPSwitch, TOPSwitch-GX is an integrated switched

mode power supply chip that converts a current at the control

input to a duty cycle at the open drain output of a high voltage

power MOSFET. During normal operation the duty cycle of

the power MOSFET decreases linearly with increasing

CONTROL pin current as shown in Figure 7.

In addition to the three terminal TOPSwitch features, such as

the high voltage start-up, the cycle-by-cycle current limiting,

loop compensation circuitry, auto-restart, thermal shutdown,

the TOPSwitch-GX incorporates many additional functions that

reduce system cost, increase power supply performance and

design flexibility. A patented high voltage CMOS technology

allows both the high voltage power MOSFET and all the low

voltage control circuitry to be cost effectively integrated onto

a single monolithic chip.

Three terminals, FREQUENCY, LINE-SENSE, and EXTER-

NAL CURRENT LIMIT (available in Y, R or F package) or

one terminal MULTI-FUNCTION (available in P or G

Package) have been added to implement some of the new

functions. These terminals can be connected to the SOURCE

pin to operate the TOPSwitch-GX in a TOPSwitch-like three

terminal mode. However , even in this three terminal mode, the

TOPSwitch-GX offers many new transparent features that do

not require any external components:

1. A fully integrated 10 ms soft-start limits peak currents and

voltages during start-up and dramatically reduces or

eliminates output overshoot in most applications.

2. DCMAX of 78% allows smaller input storage capacitor, lower

input voltage requirement and/or higher power capability.

3. Frequency reduction at light loads lowers the switching

losses and maintains good cross regulation in multiple

output supplies.

4. Higher switching frequency of 132 kHz reduces the

transformer size with no noticeable impact on EMI.

5. Frequency jittering reduces EMI.

6. Hysteretic over-temperature shutdown ensures automatic

recovery from thermal fault. Large hysteresis prevents circuit

board overheating.

7. Packages with omitted pins and lead forming provide large

drain creepage distance.

8. Tighter absolute tolerances and smaller temperature vari-

ations on switching frequency, current limit and PWM gain.

The LINE-SENSE (L) pin is usually used for line sensing by

connecting a resistor from this pin to the rectified DC high

voltage bus to implement line overvoltage (OV), under-voltage

(UV) and line feed forward with DCMAX reduction. In this

mode, the value of the resistor determines the OV/UV thresholds

and the DCMAX is reduced linearly starting from a line voltage

above the under-voltage threshold. See Table 2 and Figure 11.

The pin can also be used as a remote ON/OFF and a

synchronization input.

The EXTERNAL CURRENT LIMIT (X) pin is usually used to

reduce the current limit externally to a value close to the operat-

ing peak current, by connecting the pin to SOURCE through a

resistor. This pin can also be used as a remote ON/OFF and a

synchronization input in both modes. See Table 2 and Figure 1 1.

For the P or G packages the LINE-SENSE and EXTERNAL

CURRENT LIMIT pin functions are combined on one MULTI-

FUNCTION (M) pin. However , some of the functions become

mutually exclusive as shown in Table 3.

The FREQUENCY (F) pin in the Y, R or F package sets the

switching frequency to the default value of 132 kHz when

connected to SOURCE pin. A half frequency option of 66 kHz

can be chosen by connecting this pin to CONTROL pin

instead. Leaving this pin open is not recommended.

PI-2633-011502

Duty Cycle (%)

(mA)

TOP242-5 1.6 2.0

TOP246-9 2.2 2.6

TOP250 2.4 2.7

5.2 6.0

5.8 6.6

6.5 7.3

CD1

Auto-restart

= 125 µA

< I

L(DC)

= 190 µA

Frequency (kHz)

(mA)

CD1

Auto-restart

132

Note: For P and G packages I

is replaced with I

< I

L(DC)

= 125 µA

Slope = PWM Gain

= 190 µA

Figure 7. Relationship of Duty Cycle and Frequency to CONTROL

Pin Current.

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

PI-2545-082299

S1 S2 S6 S7 S1 S2 S6 S7S0 S1 S7

S0 S0 5.8 V

4.8 V

0 V

LINE

DRAIN

OUT

Note: S0 through S7 are the output states of the auto-restart counter

1234

0 V

S6 S7

CONTROL (C) Pin Operation

The CONTROL pin is a low impedance node that is capable of

receiving a combined supply and feedback current. During

normal operation, a shunt regulator is used to separate the feed-

back signal from the supply current. CONTROL pin voltage

VC is the supply voltage for the control circuitry including the

MOSFET gate driver. An external bypass capacitor closely

connected between the CONTROL and SOURCE pins is

required to supply the instantaneous gate drive current. The

total amount of capacitance connected to this pin also sets the

auto-restart timing as well as control loop compensation.

When rectified DC high voltage is applied to the DRAIN pin

during start-up, the MOSFET is initially off, and the

CONTROL pin capacitor is charged through a switched high

voltage current source connected internally between the DRAIN

and CONTROL pins. When the CONTROL pin voltage VC

reaches approximately 5.8 V, the control circuitry is activated

and the soft-start begins. The soft-start circuit gradually

increases the duty cycle of the MOSFET from zero to the maxi-

mum value over approximately 10 ms. If no external feedback/

supply current is fed into the CONTROL pin by the end of the

soft-start, the high voltage current source is turned off and the

CONTROL pin will start discharging in response to the supply

current drawn by the control circuitry. If the power supply is

designed properly, and no fault condition such as open loop or

shorted output exists, the feedback loop will close, providing

external CONTROL pin current, before the CONTROL pin

voltage has had a chance to discharge to the lower threshold

voltage of approximately 4.8 V (internal supply under-voltage

lockout threshold). When the externally fed current charges

the CONTROL pin to the shunt regulator voltage of 5.8 V, cur -

rent in excess of the consumption of the chip is shunted to

SOURCE through resistor RE as shown in Figure 2. This

current flowing through RE controls the duty cycle of the power

MOSFET to provide closed loop regulation. The shunt

regulator has a finite low output impedance ZC that sets the

gain of the error amplifier when used in a primary feedback

configuration. The dynamic impedance Z C of the CONTROL

pin together with the external CONTROL pin capacitance sets

the dominant pole for the control loop.

When a fault condition such as an open loop or shorted output

prevents the flow of an external current into the CONTROL

pin, the capacitor on the CONTROL pin discharges towards

4.8 V. At 4.8 V, auto-restart is activated which turns the output

MOSFET off and puts the control circuitry in a low current

standby mode. The high-voltage current source turns on and

charges the external capacitance again. A hysteretic internal

supply under-voltage comparator keeps VC within a window

of typically 4.8 V to 5.8 V by turning the high-voltage current

source on and off as shown in Figure 8. The auto-restart

circuit has a divide-by-eight counter which prevents the out-

put MOSFET from turning on again until eight discharge/charge

cycles have elapsed. This is accomplished by enabling the

output MOSFET only when the divide-by-eight counter reaches

full count (S7). The counter effectively limits TOPSwitch-GX

power dissipation by reducing the auto-restart duty cycle to

typically 4%. Auto-restart mode continues until output

voltage regulation is again achieved through closure of the

feedback loop.

Oscillator and Switching Frequency

The internal oscillator linearly charges and discharges an

internal capacitance between two voltage levels to create a

sawtooth waveform for the pulse width modulator. This

Figure 8. Typical Waveforms for (1) Power Up (2) Normal Operation (3) Auto-restart (4) Power Down.

TOP242-250

9/02

Figure 9. Switching Frequency Jitter (Idealized VDRAIN waveform).

oscillator sets the pulse width modulator/current limit latch at

the beginning of each cycle.

The nominal switching frequency of 132 kHz was chosen to

minimize transformer size while keeping the fundamental EMI

frequency below 150 kHz. The FREQUENCY pin (available

only in Y, R or F package), when shorted to the CONTROL

pin, lowers the switching frequency to 66 kHz (half frequency)

which may be preferable in some cases such as noise sensitive

video applications or a high efficiency standby mode. Other-

wise, the FREQUENCY pin should be connected to the

SOURCE pin for the default 132 kHz.

To further reduce the EMI level, the switching frequency is

jittered (frequency modulated) by approximately ±4 kHz at

250 Hz (typical) rate as shown in Figure 9. Figure 46 shows

the typical improvement of EMI measurements with frequency

jitter.

Pulse Width Modulator and Maximum Duty Cycle

The pulse width modulator implements voltage mode control

by driving the output MOSFET with a duty cycle inversely

proportional to the current into the CONTROL pin that is in

excess of the internal supply current of the chip (see Figure 7).

The excess current is the feedback error signal that appears

across RE (see Figure 2). This signal is filtered by an RC

network with a typical corner frequency of 7 kHz to reduce the

effect of switching noise in the chip supply current generated

by the MOSFET gate driver. The filtered error signal is

compared with the internal oscillator sawtooth waveform to

generate the duty cycle waveform. As the control current

increases, the duty cycle decreases. A clock signal from the

oscillator sets a latch which turns on the output MOSFET . The

pulse width modulator resets the latch, turning off the output

MOSFET. Note that a minimum current must be driven into

the CONTROL pin before the duty cycle begins to change.

The maximum duty cycle, DCMAX, is set at a default maximum

value of 78% (typical). However, by connecting the LINE-

SENSE or MULTI-FUNCTION pin (depending on the

package) to the rectified DC high voltage bus through a

resistor with appropriate value, the maximum duty cycle can

be made to decrease from 78% to 38% (typical) as shown in

Figure 11 when input line voltage increases (see line feed

forward with DCMAX reduction).

Light Load Frequency Reduction

The pulse width modulator duty cycle reduces as the load at

the power supply output decreases. This reduction in duty cycle

is proportional to the current flowing into the CONTROL pin.

As the CONTROL pin current increases, the duty cycle

decreases linearly towards a duty cycle of 10%. Below 10%

duty cycle, to maintain high efficiency at light loads, the

frequency is also reduced linearly until a minimum frequency

is reached at a duty cycle of 0% (refer to Figure 7). The

minimum frequency is typically 30 kHz and 15 kHz for

132 kHz and 66 kHz operation, respectively.

This feature allows a power supply to operate at lower

frequency at light loads thus lowering the switching losses while

maintaining good cross regulation performance and low

output ripple.

Error Amplifier

The shunt regulator can also perform the function of an error

amplifier in primary side feedback applications. The shunt

regulator voltage is accurately derived from a temperature-

compensated bandgap reference. The gain of the error ampli-

fier is set by the CONTROL pin dynamic impedance. The

CONTROL pin clamps external circuit signals to the VC

voltage level. The CONTROL pin current in excess of the

supply current is separated by the shunt regulator and flows

through RE as a voltage error signal.

On-chip Current Limit with External Programmability

The cycle-by-cycle peak drain current limit circuit uses the out-

put MOSFET ON-resistance as a sense resistor. A current limit

comparator compares the output MOSFET on-state drain to

source voltage, VDS(ON) with a threshold voltage. High drain

current causes VDS(ON) to exceed the threshold voltage and turns

the output MOSFET off until the start of the next clock cycle.

The current limit comparator threshold voltage is temperature

compensated to minimize the variation of the current limit due to

temperature related changes in RDS(ON) of the output MOSFET.

The default current limit of TOPSwitch-GX is preset internally.

However, with a resistor connected between EXTERNAL

CURRENT LIMIT (X) pin (Y, R or F package) or MULTI-

FUNCTION (M) pin (P or G package) and SOURCE pin,

current limit can be programmed externally to a lower level

between 30% and 100% of the default current limit. Please refer

to the graphs in the typical performance characteristics section

for the selection of the resistor value. By setting current limit

low, a larger TOPSwitch-GX than necessary for the power

required can be used to take advantage of the lower RDS(ON) for

higher efficiency/smaller heat sinking requirements. With a

second resistor connected between the EXTERNAL

PI-2550-092499

128 kHz

4 ms

Time

Switching

Frequency

DRAIN

136 kHz

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Figure 10. Synchronization Timing Diagram.

PI-2637-060600

Oscillator

(SAW)

DMAX

Enable from

X, L or M Pin (STOP) Time

CURRENT LIMIT (X) pin (Y, R or F package) or MULTI-

FUNCTION (M) pin (P or G package) and the rectified DC

high voltage bus, the current limit is reduced with increasing

line voltage, allowing a true power limiting operation against

line variation to be implemented. When using an RCD clamp,

this power limiting technique reduces maximum clamp

voltage at high line. This allows for higher reflected voltage

designs as well as reducing clamp dissipation.

The leading edge blanking circuit inhibits the current limit

comparator for a short time after the output MOSFET is turned

on. The leading edge blanking time has been set so that, if a

power supply is designed properly, current spikes caused by

primary-side capacitances and secondary-side rectifier reverse

recovery time should not cause premature termination of the

switching pulse.

The current limit is lower for a short period after the leading

edge blanking time as shown in Figure 52. This is due to

dynamic characteristics of the MOSFET. To avoid triggering

the current limit in normal operation, the drain current wave-

form should stay within the envelope shown.

Line Under-Voltage Detection (UV)

At power up, UV keeps TOPSwitch-GX off until the input line

voltage reaches the under voltage threshold. At power down,

UV prevents auto-restart attempts after the output goes out of

regulation. This eliminates power down glitches caused by

the slow discharge of large input storage capacitor present in

applications such as standby supplies. A single resistor

connected from the LINE-SENSE pin (Y, R or F package) or

MULTI-FUNCTION pin (P or G package) to the rectified DC

high voltage bus sets UV threshold during power up. Once the

power supply is successfully turned on, the UV threshold is

lowered to 40% of the initial UV threshold to allow extended

input voltage operating range (UV low threshold). If the UV

low threshold is reached during operation without the power

supply losing regulation the device will turn off and stay off

until UV (high threshold) has been reached again. If the power

supply loses regulation before reaching the UV low threshold,

the device will enter auto-restart. At the end of each auto-

restart cycle (S7), the UV comparator is enabled. If the UV high

threshold is not exceeded the MOSFET will be disabled during

the next cycle (see Figure 8). The UV feature can be disabled

independent of OV feature as shown in Figures 19 and 23.

Line Overvoltage Shutdown (OV)

The same resistor used for UV also sets an overvoltage thresh-

old which, once exceeded, will force TOPSwitch-GX output

into off-state. The ratio of OV and UV thresholds is preset at

4.5 as can be seen in Figure 1 1. When the MOSFET is off, the

rectified DC high voltage surge capability is increased to the

voltage rating of the MOSFET (700 V), due to the absence of

the reflected voltage and leakage spikes on the drain. A small

amount of hysteresis is provided on the OV threshold to

prevent noise triggering. The OV feature can be disabled

independent of the UV feature as shown in Figures 18 and 32.

Line Feed Forward with DCMAX Reduction

The same resistor used for UV and OV also implements line

voltage feed forward which minimizes output line ripple and

reduces power supply output sensitivity to line transients. This

feed forward operation is illustrated in Figure 7 by the

different values of IL (Y, R or F package) or IM (P or G Pack-

age). Note that for the same CONTROL pin current, higher

line voltage results in smaller operating duty cycle. As an added

feature, the maximum duty cycle DCMAX is also reduced from

78% (typical) at a voltage slightly higher than the UV thresh-

old to 30% (typical) at the OV threshold (see Figures 7 and

11). Limiting DCMAX at higher line voltages helps

TOP242-250

9/02

prevent transformer saturation due to large load transients in

forward converter applications. DCMAX of 38% at the OV thresh-

old was chosen to ensure that the power capability of the

TOPSwitch-GX is not restricted by this feature under normal

operation.

Remote ON/OFF and Synchronization

TOPSwitch-GX can be turned on or off by controlling the current

into the LINE-SENSE pin or out from the EXTERNAL

CURRENT LIMIT pin (Y, R or F package) and into or out from

the MULTI-FUNCTION pin (P or G package) (see Figure 11).

In addition, the LINE-SENSE pin has a 1 V threshold compara-

tor connected at its input. This voltage threshold can also be used

to perform remote ON/OFF control. This allows easy implemen-

tation of remote ON/OFF control of TOPSwitch-GX in several

different ways. A transistor or an optocoupler output connected

between the EXTERNAL CURRENT LIMIT or LINE-SENSE

pins (Y, R or F package) or the MULTI-FUNCTION pin (P or G

package) and the SOURCE pin implements this function with

“active-on” (Figures 22, 29 and 36) while a transistor or an

optocoupler output connected between the LINE-SENSE pin

(Y, R or F package) or the MUL TI-FUNCTION (P or G package)

pin and the CONTROL pin implements the function with

“active-off” (Figures 23 and 37).

When a signal is received at the LINE-SENSE pin or the

EXTERNAL CURRENT LIMIT pin (Y, R or F package) or

the MULTI-FUNCTION pin (P or G package) to disable the

output through any of the pin functions such as OV, UV and

remote ON/OFF, TOPSwitch-GX always completes its current

switching cycle, as illustrated in Figure 10, before the output is

forced off. The internal oscillator is stopped slightly before the

end of the current cycle and stays there as long as the disable

signal exists. When the signal at the above pins changes state

from disable to enable, the internal oscillator starts the next

switching cycle. This approach allows the use of these pins to

synchronize TOPSwitch-GX to any external signal with a

frequency between its internal switching frequency and 20 kHz.

As seen above, the remote ON/OFF feature allows the

TOPSwitch-GX to be turned on and off instantly, on a cycle-

by-cycle basis, with very little delay. However, remote

ON/OFF can also be used as a standby or power switch to turn

off the TOPSwitch-GX and keep it in a very low power

consumption state for indefinitely long periods. If the

TOPSwitch-GX is held in remote off state for long enough time

to allow the CONTROL pin to dishcharge to the internal

supply under-voltage threshold of 4.8 V (approximately 32 ms

for a 47 µF CONTROL pin capacitance), the CONTROL pin

goes into the hysteretic mode of regulation. In this mode, the

CONTROL pin goes through alternate charge and discharge

cycles between 4.8 V and 5.8 V (see CONTROL pin operation

section above) and runs entirely off the high voltage DC input,

but with very low power consumption (160 mW typical at

230 VAC with M or X pins open). When the TOPSwitch-GX is

remotely turned on after entering this mode, it will initiate a

normal start-up sequence with soft-start the next time the

CONTROL pin reaches 5.8 V. In the worst case, the delay from

remote on to start-up can be equal to the full discharge/char ge

cycle time of the CONTROL pin, which is approximately

125 ms for a 47 µF CONTROL pin capacitor. This

reduced consumption remote off mode can eliminate

expensive and unreliable in-line mechanical switches. It also

allows for microprocessor controlled turn-on and turn-off

sequences that may be required in certain applications such as

inkjet and laser printers.

Soft-Start

Two on-chip soft-start functions are activated at start-up with

a duration of 10 ms (typical). Maximum duty cycle starts from

0% and linearly increases to the default maximum of 78% at

the end of the 10 ms duration and the current limit starts from

about 85% and linearly increases to 100% at the end of the

10ms duration. In addition to start-up, soft-start is also

activated at each restart attempt during auto-restart and when

restarting after being in hysteretic regulation of CONTROL

pin voltage (VC), due to remote off or thermal shutdown

conditions. This effectively minimizes current and voltage

stresses on the output MOSFET, the clamp circuit and the

output rectifier during start-up. This feature also helps

minimize output overshoot and prevents saturation of the

transformer during start-up.

Shutdown/Auto-Restart

To minimize TOPSwitch-GX power dissipation under fault

conditions, the shutdown/auto-restart circuit turns the power

supply on and off at an auto-restart duty cycle of typically 4%

if an out of regulation condition persists. Loss of regulation

interrupts the external current into the CONTROL pin. VC regu-

lation changes from shunt mode to the hysteretic auto-restart

mode as described in CONTROL pin operation section. When

the fault condition is removed, the power supply output

becomes regulated, VC regulation returns to shunt mode, and

normal operation of the power supply resumes.

Hysteretic Over-Temperature Protection

Temperature protection is provided by a precision analog

circuit that turns the output MOSFET off when the junction

temperature exceeds the thermal shutdown temperature

(140 °C typical). When the junction temperature cools to

below the hysteretic temperature, normal operation resumes

providing automatic recovery. A large hysteresis of 70 °C

(typical) is provided to prevent overheating of the PC board

due to a continuous fault condition. VC is regulated in hyster-

etic mode and a 4.8 V to 5.8 V (typical) sawtooth waveform is

present on the CONTROL pin while in thermal shutdown.

Bandgap Reference

All critical TOPSwitch-GX internal voltages are derived from

a temperature-compensated bandgap reference. This reference

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

is also used to generate a temperature-compensated current

reference which is trimmed to accurately set the switching

frequency, MOSFET gate drive current, current limit, and the

line OV/UV thresholds. TOPSwitch-GX has improved circuitry

to maintain all of the above critical parameters within very tight

absolute and temperature tolerances.

High-Voltage Bias Current Source

This current source biases TOPSwitch-GX from the DRAIN

pin and charges the CONTROL pin external capacitance

during start-up or hysteretic operation. Hysteretic operation

occurs during auto-restart, remote off and over-temperature

shutdown. In this mode of operation, the current source is

switched on and off with an effective duty cycle of approxi-

mately 35%. This duty cycle is determined by the ratio of

CONTROL pin charge (IC) and discharge currents (ICD1 and

ICD2). This current source is turned off during normal

operation when the output MOSFET is switching. The effect

of the current source switching will be seen on the DRAIN

voltage waveform as small disturbances and is normal.

TOP242-250

9/02

FREQUENCY (F) Pin Operation

The FREQUENCY pin is a digital input pin available in the

Y, R or F package only. Shorting the FREQUENCY pin to

SOURCE pin selects the nominal switching frequency of

132 kHz (Figure 13) which is suited for most applications. For

other cases that may benefit from lower switching

frequency such as noise sensitive video applications, a 66 kHz

switching frequency (half frequency) can be selected by

shorting the FREQUENCY pin to the CONTROL pin

(Figure 14). In addition, an example circuit shown in Figure 15

may be used to lower the switching frequency from 132 kHz in

normal operation to 66 kHz in standby mode for very low standby

power consumption.

LINE-SENSE (L) Pin Operation (Y, R and F Packages)

When current is fed into the LINE-SENSE pin, it works as a

voltage source of approximately 2.6 V up to a maximum

current of +400 µA (typical). At +400 µA, this pin turns into a

constant current sink. Refer to Figure 12a. In addition, a

comparator with a threshold of 1 V is connected at the pin and is

used to detect when the pin is shorted to the SOURCE pin.

There are a total of four functions available through the use of

the LINE-SENSE pin: OV, UV, line feed forward with DCMAX

reduction, and remote ON/OFF. Connecting the LINE-SENSE

pin to the SOURCE pin disables all four functions. The LINE-

SENSE pin is typically used for line sensing by connecting a

resistor from this pin to the rectified DC high voltage bus to imple-

ment OV, UV and DCMAX reduction with line voltage. In this

mode, the value of the resistor determines the line OV/UV thresh-

olds, and the DCMAX is reduced linearly with rectified DC high

voltage starting from just above the UV threshold. The pin can

also be used as a remote on/off and a synchronization input. Refer

to Table 2 for possible combinations of the functions with

Using Feature Pins

✔

✔✔ ✔✔✔

✔✔✔✔

✔

✔✔ ✔✔ ✔✔

✔✔✔✔✔✔ ✔

16 17 18 19 20 21 22 23 24 25 26 27 28 29

Table 2. Typical LINE-SENSE and EXTERNAL CURRENT LIMIT Pin Configurations.

*This table is only a partial list of many LINE-SENSE and EXTERNAL CURRENT LIMIT pin configurations that are possible.

▲

Figure Number

Three Terminal Operation

Under-Voltage

Overvoltage

Line Feed Forward (DCMAX)

Overload Power Limiting

External Current Limit

Remote ON/OFF

example circuits shown in Figure 16 through Figure 40. A

description of specific functions in terms of the LINE-SENSE

pin I/V characteristic is shown in Figure 11 (right hand side).

The horizontal axis represents LINE-SENSE pin current with

positive polarity indicating currents flowing into the pin. The

meaning of the vertical axes varies with functions. For those

that control the on/off states of the output such as UV, OV and

remote ON/OFF, the vertical axis represents the enable/

disable states of the output. UV triggers at IUV (+50 µA typical

with 30 µA hysteresis) and OV triggers at IOV (+225 µA

typical with 8 µA hysteresis). Between the UV and OV thresh-

olds, the output is enabled. For line feed forward with DCMAX

reduction, the vertical axis represents the magnitude of the

DCMAX. Line feed forward with DCMAX reduction lowers

maximum duty cycle from 78% at IL(DC) (+60 µA typical) to

38% at IOV (+225 µA).

EXTERNAL CURRENT LIMIT (X) Pin Operation

(Y, R and F Packages)

When current is drawn out of the EXTERNAL CURRENT

LIMIT pin, it works as a voltage source of approximately

1.3 V up to a maximum current of –240 µA (typical). At

–240 µA, it turns into a constant current source (refer to

Figure 12a).

There are two functions available through the use of the

EXTERNAL CURRENT LIMIT pin: external current limit

and remote ON/OFF . Connecting the EXTERNAL CURRENT

LIMIT pin and SOURCE pin disables the two functions. In

high efficiency applications this pin can be used to reduce the

current limit externally to a value close to the operating peak

current, by connecting the pin to the SOURCE pin through a

resistor. The pin can also be used for remote on/off. Table 2

shows several possible combinations using this pin. See

LINE-SENSE AND EXTERNAL CURRENT LIMIT PIN TABLE*

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

✔

✔✔ ✔

✔✔

✔

✔✔ ✔✔

✔✔ ✔ ✔ ✔

Table 3. Typical MULTI-FUNCTION Pin Configurations.

MULTI-FUNCTION PIN TABLE*

30 31 32 33 34 35 36 37 38 39 40

▲

Figure Number

Three Terminal Operation

Under-Voltage

Overvoltage

Line Feed Forward (DCMAX)

Overload Power Limiting

External Current Limit

Remote ON/OFF

Figure 1 1 for a description of the functions where the horizon-

tal axis (left hand side) represents the EXTERNAL CURRENT

LIMIT pin current. The meaning of the vertical axes varies

with function. For those that control the on/off states of the

output such as remote ON/OFF, the vertical axis represents the

enable/disable states of the output. For external current limit,

the vertical axis represents the magnitude of the ILIMIT. Please

see graphs in the typical performance characteristics section

for the current limit programming range and the selection of

appropriate resistor value.

MULTI-FUNCTION (M) Pin Operation (P and G Packages)

The LINE-SENSE and EXTERNAL CURRENT LIMIT pin

functions are combined to a single MULTI-FUNCTION pin

for P and G packages. The comparator with a 1 V threshold at

the LINE-SENSE pin is removed in this case as shown in

Figure 2b. All of the other functions are kept intact. However,

since some of the functions require opposite polarity of input

current (MULTI-FUNCTION pin), they are mutually

exclusive. For example, line sensing features cannot be used

simultaneously with external current limit setting. When

current is fed into the MULTI-FUNCTION pin, it works as a

voltage source of approximately 2.6 V up to a maximum

current of +400 µA (typical). At +400 µA, this pin turns into a

constant current sink. When current is drawn out of the MULTI-

FUNCTION pin, it works as a voltage source of

approximately 1.3 V up to a maximum current of –240 µA

(typical). At –240 µA, it turns into a constant current source.

Refer to Figure 12b.

There are a total of five functions available through the use of

the MULTI-FUNCTION pin: OV, UV, line feed forward with

DCMAX reduction, external current limit and remote ON/OFF.

A short circuit between the MULTI-FUNCTION pin and

SOURCE pin disables all five functions and forces

TOPSwitch-GX to operate in a simple three terminal mode like

TOPSwitch-II. The MULTI-FUNCTION pin is typically used

for line sensing by connecting a resistor from this pin to the

rectified DC high voltage bus to implement OV, UV and DCMAX

reduction with line voltage. In this mode, the value of the

resistor determines the line OV/UV thresholds, and the DCMAX

is reduced linearly with rectified DC high voltage starting from

just above the UV threshold. In high efficiency applications

this pin can be used in the external current limit mode instead,

to reduce the current limit externally to a value close to the

operating peak current, by connecting the pin to the SOURCE

pin through a resistor. The same pin can also be used as a

remote on/off and a synchronization input in both modes. Please

refer to Table 3 for possible combinations of the functions with

example circuits shown in Figure 30 through Figure 40. A

description of specific functions in terms of the MULTI-

FUNCTION pin I/V characteristic is shown in Figure 11. The

horizontal axis represents MUL TI-FUNCTION pin current with

positive polarity indicating currents flowing into the pin. The

meaning of the vertical axes varies with functions. For those

that control the on/off states of the output such as UV, OV and

remote ON/OFF, the vertical axis represents the enable/

disable states of the output. UV triggers at IUV (+50 µA

typical) and OV triggers at IOV (+225 µA typical with 30 µA

hysteresis). Between the UV and OV thresholds, the output is

enabled. For external current limit and line feed forward with

DCMAX reduction, the vertical axis represents the magnitude of

the ILIMIT and DCMAX. Line feed forward with DCMAX reduction

lowers maximum duty cycle from 78% at IM(DC) (+60 µA

typical) to 38% at IOV (+225 µA). External current limit is

available only with negative MULTI-FUNCTION pin current.

Please see graphs in the typical performance characteristics

section for the current limit programming range and the

selection of appropriate resistor value.

*This table is only a partial list of many MULTI-FUNCTION pin configurations that are possible.

TOP242-250

9/02

Figure 11. MULTI-FUNCTION (P or G package), LINE-SENSE, and EXTERNAL CURRENT LIMIT (Y, R or F package) Pin Characteristics.

-250 -200 -150 -100 -50 0 50 100 150 200 250 300 350 400

PI-2636-010802

Output

MOSFET

Switching

(Enabled)

(Disabled)

LIMIT

(Default)

MAX

(78.5%)

Current

Limit

M Pin

L PinX Pin

Maximum

Duty Cycle

-22 µA

-27 µAV

+ V

REM(N)

Pin Voltage

Note: This figure provides idealized functional characteristics with typical performance values. Please refer to the parametric

table and typical performance characteristics sections of the data sheet for measured data.

X and L Pins (Y, R or F Package) and M Pin (P or G Package) Current (µA)

Disabled when supply

output goes out of

regulation

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Figure 12a. LINE-SENSE (L), and EXTERNAL CURRENT LIMIT (X) Pin Input Simplified Schematic.

Figure 12b. MULTI-FUNCTION (M) Pin Input Simplified Schematic.

+ V

1 V

240 µA

400 µA

CONTROL Pin

Y, R and F Package

(Voltage Sense)

(Positive Current Sense - Under-Voltage,

Overvoltage, ON/OFF Maximum Duty

Cycle Reduction)

(Negative Current Sense - ON/OFF,

Current Limit Adjustment)

PI-2634-010802

TOPSwitch-GX

LINE-SENSE (L)

EXTERNAL CURRENT LIMIT (X)

+ V

240 µA

400 µA

CONTROL Pin

MULTI-FUNCTION (M)

(Positive Current Sense - Under-Voltage,

Overvoltage, Maximum Duty

Cycle Reduction)

(Negative Current Sense - ON/OFF,

Current Limit Adjustment)

PI-2548-092399

TOPSwitch-GX

P and G Package

TOP242-250

9/02

Figure 15. Half Frequency Standby Mode (For High Standby

Efficiency).

Figure 13. Full Frequency Operation (132 kHz). Figure 14. Half Frequency Operation (66 kHz).

Typical Uses of FREQUENCY (F) Pin

PI-2654-071700

Input

Voltage

CONTROL

PI-2655-071700

Input

Voltage

CONTROL

PI-2656-040501

Input

Voltage

STANDBY

QS can be an optocoupler output.

CONTROL

20 kΩ

RHF 1 nF

QS47 kΩ

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins

PI-2617-050100

Input

Voltage

DCS D

CONTROL

CLXSF D

PI-2618-040501

Input

Voltage

CONTROL

2MΩR

= I

x R

For R

= 2 MΩ

= 100 VDC

450 VDC

MAX

@100 VDC = 78%

MAX

@375 VDC = 38%

PI-2510-040501

Input

Voltage

= R

x I

For Value Shown

= 100 VDC

6.2 V

2 MΩ

22 kΩ

CONTROL

PI-2620-040501

Input

Voltage

CONTROL

2 MΩ

30 kΩ

1N4148

= I

For Values Shown

= 450 VDC

PI-2623-040501

Input

Voltage

For R

= 12 kΩ

LIMIT

= 69%

See fig. 55 for other

resistor values (R

)

For R

= 25 kΩ

LIMIT

= 43%

CONTROL

PI-2624-040501

Input

Voltage

2.5 MΩR

6 kΩ

100% @ 100 VDC

63% @ 300 VDC

LIMIT

CONTROL

Figure 16. Three Terminal Operation (LINE-SENSE and

EXTERNAL CURRENT LIMIT Features Disabled.

FREQUENCY Pin can be tied to SOURCE or

CONTROL Pin).

Figure 17. Line-Sensing for Under-Voltage, Overvoltage and

Line Feed Forward.

Figure 18. Line-Sensing for Under-Voltage Only (Overvoltage

Disabled). Figure 19. Line-Sensing for Overvoltage Only (Under-Voltage

Disabled). Maximum Duty Cycle will be reduced at

Low Line.

Figure 20. Externally Set Current Limit. Figure 21. Current Limit Reduction with Line Voltage.

TOP242-250

9/02

Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins (cont.)

Figure 22. Active-on (Fail Safe) Remote ON/OFF.

PI-2625-040501

Input

Voltage

ON/OFF

47 kΩ

can be an optocoupler

output or can be replaced by

a manual switch.

CONTROL

ON/OFF

47 kΩ

PI-2626-040501

Input

Voltage

RIL QR

12 kΩ

For RIL =

ILIMIT = 69 %

25 kΩ

For RIL =

ILIMIT = 43 %

QR can be an optocoupler

output or can be replaced

by a manual switch.

CONTROL

PI-2627-040501

Input

Voltage

CONTROL

47 kΩ

45 kΩ

QR can be an

optocoupler output

or can be replaced

by a manual switch.

ON/OFF

PI-2622-040501

Input

Voltage

CONTROL

47 kΩ

2 MΩ

ON/OFF For RLS = 2 MΩ

VUV = 100 VDC

VOV = 450 VDC

QR can be an optocoupler

output or can be replaced

by a manual switch.

ON/OFF

47 kΩ

PI-2628-040501

Input

Voltage

CONTROL

2 MΩ

= I

x R

MAX

@100 VDC = 78%

MAX

@375 VDC = 38%

12 kΩ

For R

LIMIT

= 69 %

can be an optocoupler

output or can be replaced

by a manual switch.

Figure 23. Active-off Remote ON/OFF. Maximum Duty Cycle will

be reduced.

Figure 24. Active-on Remote ON/OFF with Externally Set Current

Limit. Figure 25. Active-off Remote ON/OFF with Externally Set Current

Limit.

Figure 26. Active-off Remote ON/OFF with LINE-SENSE. Figure 27. Active-on Remote ON/OFF with LINE-SENSE and

EXTERNAL CURRENT LIMIT.

PI-2621-040501

Input

Voltage

CONTROL

47 kΩ

45 kΩ

QR can be an

optocoupler output or

can be replaced

by a manual switch.

ON/OFF

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins (cont.)

Figure 28. Line-Sensing and Externally Set Current Limit.

PI-2640-040501

Input

Voltage

CONTROL

ON/OFF

47 kΩ

can be an optocoupler

output or can be replaced by

a manual switch.

300 kΩ

Figure 29. Active-on Remote ON/OFF.

PI-2629-040501

Input

Voltage

CONTROL

12 kΩ

2 MΩ

= I

x R

For R

= 2 MΩ

MAX

@100 VDC = 78%

MAX

@375 VDC = 38%

For R

= 12 kΩ

LIMIT

= 69%

See fig. 55 for other

resistor values (R

)

to select different I

LIMIT

values

= 100 VDC

= 450 VDC

TOP242-250

9/02

Figure 32. Line Sensing for Under-Voltage Only (Overvoltage

Disabled).

PI-2510-040501

Input

Voltage

VUV = RLS x IUV

For Value Shown

VUV = 100 VDC

6.2 V

2 MΩ

22 kΩ

CONTROL

Figure 33. Line Sensing for Overvoltage Only (Under-Voltage

Disabled). Maximum Duty Cycle will be reduced at

Low Line.

Figure 34. Externally Set Current Limit.

PI-2517-040501

Input

Voltage

For RIL = 12 kΩ

ILIMIT = 69%

CONTROL

RIL

See fig. 55 for other

resistor values (RIL)

For RIL = 25 kΩ

ILIMIT = 43%

to select different

ILIMIT values

PI-2516-040501

Input

Voltage

VOV = IOV x RLS

For Values Shown

VOV = 450 VDC

CONTROL

1N4148

2 MΩ

30 kΩ

Figure 30. Three Terminal Operation (MULTI-FUNCTION

Features Disabled).

PI-2508-081199

Input

Voltage

CONTROL

CD S

PI-2509-040501

Input

Voltage

VUV = IUV x RLS

VOV = IOV x RLS

For RLS = 2 MΩ

VUV = 100 VDC

VOV = 450 VDC

DCMAX@100 VDC = 78%

DCMAX@375 VDC = 38%

CONTROL

2 MΩ

Typical Uses of MULTI-FUNCTION (M) Pin

Figure 35. Current Limit Reduction with Line Voltage.

PI-2518-040501

Input

Voltage

CONTROL

RIL

RLS 2.5 MΩ

6 kΩ

100% @ 100 VDC

63% @ 300 VDC

ILIMIT =

Figure 31. Line Sensing for Undervoltage, Over-Voltage and

Line Feed Forward.

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

PI-2522-040501

Input

Voltage

RMC

45 kΩ

CONTROL

QR can be an optocoupler

output or can be replaced

by a manual switch.

ON/OFF 47 kΩ

Figure 37. Active-off Remote ON/OFF. Maximum Duty Cycle will

be Reduced.

Figure 36. Active-on (Fail Safe) Remote ON/OFF.

PI-2519-040501

Input

Voltage

ON/OFF

CONTROL

can be an optocoupler

output or can be replaced

by a manual switch.

47 kΩ

PI-2523-040501

Input

Voltage

M For R

= 2 MΩ

= 100 VDC

= 450 VDC

CONTROL

2 MΩ

can be an optocoupler

output or can be replaced

by a manual switch.

ON/OFF 47 kΩ

Figure 40. Active-off Remote ON/OFF with LINE-SENSE.

Figure 39. Active-off Remote ON/OFF with Externally Set

Current Limit.

PI-2521-040501

Input

Voltage

24 kΩ

12 kΩ

CONTROL

can be an optocoupler

output or can be replaced

by a manual switch.

ON/OFF 47 kΩ

Figure 38. Active-on Remote ON/OFF with Externally Set

Current Limit.

PI-2520-040501

Input

Voltage

CONTROL

12 kΩ

For R

LIMIT

= 69 %

can be an optocoupler

output or can be replaced

by a manual switch.

ON/OFF 47 kΩ

25 kΩ

For R

LIMIT

= 43 %

Typical Uses of MULTI-FUNCTION (M) Pin (cont.)

TOP242-250

9/02

Figure 41. 30 W Power Supply using External Current Limit Programming and Line Sensing for UV and OV.

Application Examples

A High Efficiency, 30 W, Universal Input Power Supply

The circuit shown in Figure 41 takes advantage of several of

the TOPSwitch-GX features to reduce system cost and power

supply size and to improve efficiency. This design delivers

30 W at 12 V, from an 85 to 265 VAC input, at an ambient of

50 °C, in an open frame configuration. A nominal efficiency

of 80% at full load is achieved using TOP244Y.

The current limit is externally set by resistors R1 and R2 to a

value just above the low line operating peak DRAIN current

of approximately 70% of the default current limit. This allows

use of a smaller transformer core size and/or higher transformer

primary inductance for a given output power, reducing

TOPSwitch-GX power dissipation, while at the same time

avoiding transformer core saturation during startup and output

transient conditions. The resistors R1 & R2 provide a signal

that reduces the current limit with increasing line voltage, which

in turn limits the maximum overload power at high input line

voltage. This function in combination with the built-in soft-

start feature of TOPSwitch-GX, allows the use of a low cost

RCD clamp (R3, C3 and D1) with a higher reflected voltage,

by safely limiting the TOPSwitch-GX drain voltage, with

adequate margin under worst case conditions. Resistor R4

provides line sensing, setting UV at 100 VDC and OV at

450 VDC. The extended maximum duty cycle feature of

TOPSwitch-GX (guaranteed minimum value of 75% vs. 64%

for TOPSwitch-II) allows the use of a smaller input capacitor

(C1). The extended maximum duty cycle and the higher

reflected voltage possible with the RCD clamp also permit the

use of a higher primary to secondary turns ratio for T1 which

reduces the peak reverse voltage experienced by the secondary

rectifier D8. As a result a 60 V Schottky rectifier can be used

for up to 15 V outputs, which greatly improves power supply

efficiency. The frequency reduction feature of the

TOPSwitch-GX eliminates the need for any dummy loading

for regulation at no load and reduces the no load/standby

consumption of the power supply. Frequency jitter provides

improved margin for conducted EMI meeting the CISPR 22

(FCC B) specification.

Output regulation is achieved by using a simple Zener sense

circuit for low cost. The output voltage is determined by the

Zener diode (VR2) voltage and the voltage drops across the

optocoupler (U2) LED and resistor R6. Resistor R8 provides

bias current to Zener VR2 for typical regulation of ±5% at the

12 V output level, over line and load and component

variations.

12 V

@ 2.5 A

1N4148

47 µF

10 V

LTV817A

VR2

1N5240C

10 V, 2%

150 Ω

R15

150 Ω

C14

1 nF

UF4005

68 kΩ

2 W

4.7 nF

1 kV

CY1

2.2 nF

TOP244Y

SXF

150 Ω

68 µF

400 V

0.1 µF

MBR1060 C10

560 µF

35 V

C12

220 µF

35 V

C11

560 µF

35 V RTN

6.8 Ω

4.7 MΩ

1/2 W

2 MΩ

1/2 W

9.09 kΩ

PI-2657-040501

3.3 µH

BR1

600 V

3.15 A

20 mH

CX1

100 nF

250 VAC

CONTROL

TOPSwitch-GX

PERFORMANCE SUMMARY

Output Power: 30 W

Regulation: ± 4%

Efficiency: ≥ 79%

Ripple: ≤ 50 mV pk-pk

85-265 VAC

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

A High Efficiency, Enclosed, 70 W, Universal Adapter Supply

The circuit shown in figure 42 takes advantage of several of the

TOPSwitch-GX features to reduce cost, power supply size and

increase efficiency. This design delivers 70 W at 19 V, from an

85 to 265 VAC input, at an ambient of 40 °C, in a small sealed

adapter case (4” x 2.15” x 1”). Full load efficiency is 85% at 85

VAC rising to 90% at 230 VAC input.

Due to the thermal environment of a sealed adapter a T OP249Y

is used to minimize device dissipation. Resistors R9 and R10

externally program the current limit level to just above the

operating peak DRAIN current at full load and low line. This

allows the use of a smaller transformer core size without

saturation during startup or output load transients. Resistors R9

and R10 also reduce the current limit with increasing line

voltage, limiting the maximum overload power at high input

line voltage, removing the need for any protection circuitry on

the secondary. Resistor R11 implements an under voltage and

over voltage sense as well as providing line feed forward for

reduced output line frequency ripple. With resistor R11 set at

2 MΩ the power supply does not start operating until the DC rail

voltage reaches 100 VDC. On removal of the AC input the UV

sense prevents the output glitching as C1 discharges,

turning off the TOPSwitch-GX when the output regulation is lost

or when the input voltage falls to below 40 V, whichever

occurs first. This same value of R11 sets the OV threshold to

450 V. If exceeded, for example during a line surge,

TOPSwitch-GX stops switching for the duration of the surge

extending the high voltage withstand to 700 V without device

Figure 42. 70 W Power Supply using Current Limit Reduction with Line and Line Sensing for UV and OV.

damage. Capacitor C11 has been added in parallel with VR1 to

reduce Zener clamp dissipation. With a switching frequency of

132 kHz a PQ26/20 core can be used to provide 70 W. To

maximize efficiency, by reducing winding losses, two output

windings are used each with their own dual 100 V Schottky

rectifier (D2 and D3). The frequency reduction feature of the

TOPSwitch-GX eliminates any dummy loading to maintain

regulation at no-load and reduces the no-load consumption of the

power supply to only 520 mW at 230 VAC input. Frequency

jittering provides conducted EMI meeting the CISPR 22

(FCC B) / EN55022B specification, using simple filter compo-

nents (C7, L2, L3 and C6) even with the output earth grounded.

To regulate the output an optocoupler (U2) is used with a

secondary reference sensing the output voltage via a resistor

divider (U3, R4, R5, R6). Diode D4 and C15 filter and smooth

the output of the bias winding. Capacitor C15 (1µF) prevents the

bias voltage from falling during zero to full load transients.

Resistor R8 provides filtering of leakage inductance spikes

keeping the bias voltage constant even at high output loads.

Resistor R7, C9 and C10 together with C5 and R3 provide loop

compensation.

Due to the large primary currents, all the small signal control

components are connected to a separate source node that is Kelvin

connected to the source pin of the TOPSwitch-GX. For improved

common mode surge immunity the bias winding common re-

turns directly to the DC bulk capacitor (C1).

19 V

@ 3.6 A

TOP249Y

TL431

PC817A

SXF

RTN

820 µH

2 A

0.1 µF

3.15 A

85-265 VAC

BR1

RS805

8 A 600 V

75 µH

2 A

t°

C13

0.33 µF

400 V

C12

0.022 µF

400 V

C11

0.01 µF

400 V

RT1

10 Ω

1.7 A

PI-2691-033001

CONTROL

TOPSwitch-GX

150 µF

400 V

47 µF

16 V

820 µF

25 V L1

200 µH

820 µF

25 V

C14

0.1 µF

50 V

820 µF

25 V

C10

0.1 µF

50 V

4.7 nF 50 V

0.1 µF

50 V

VR1

P6KE-

200

MBR20100

C7 2.2 nF

Y1 Safety

MBR20100

1N4148

R11

2 MΩ

1/2 W

13 MΩ

4.7 Ω

270 Ω

1 kΩR13

562 Ω

31.6 kΩ

56 kΩ

R10

20.5 kΩ

6.8 Ω

4.75 kΩ

C15

1 µF

50 V

UF4006

PERFORMANCE SUMMARY

Output Power: 70 W

Regulation: ± 4%

Efficiency: ≥ 84%

Ripple: < 120 mV pk-pk

No Load Consumption: < 0.52 W @ 230 VAC

TOP242-250

9/02

A High Efficiency, 250 W, 250 – 380 VDC Input Power Supply

The circuit shown in figure 43 delivers 250 W (48 V @ 5.2 A)

at 84% efficiency using a TOP249 from a 250 to 380 VDC

input. DC input is shown, as typically at this power level a

p.f.c. boost stage would preceed this supply, providing the DC

input (C1 is included to provide local decoupling). Flyback

topology is still useable at this power level due to the high

output voltage, keeping the secondary peak currents low enough

so that the output diode and capacitors are reasonably sized.

In this example the TOP249 is at the upper limit of its power

capability and the current limit is set to the internal maximum

by connecting the X pin to SOURCE. However, line sensing

is implemented by connecting a 2 MΩ resistor from the L pin

to the DC rail. If the DC input rail rises above 450 VDC, then

TOPSwitch-GX will stop switching until the voltage returns to

normal, preventing device damage.

Due to the high primary current, a low leakage inductance

transformer is essential. Therefore, a sandwich winding with

a copper foil secondary was used. Even with this technique

the leakage inductance energy is beyond the power capability

of a simple Zener clamp. Therefore, R2, R3 and C6 are added

in parallel to VR1. These have been sized such that during

normal operation very little power is dissipated by VR1, the

leakage energy instead being dissipated by R2 and R3.

However, VR1 is essential to limit the peak drain voltage

during start-up and/or overload conditions to below the 700 V

rating of the TOPSwitch-GX MOSFET.

The secondary is rectifed and smoothed by D2 and C9, C10

and C11. Three capacitors are used to meet the secondary ripple

current requirement. Inductor L2 and C12 provide switching

noise filtering.

A simple Zener sensing chain regulates the output voltage. The

sum of the voltage drop of VR2, VR3 and VR4 plus the LED

drop of U2 gives the desired output voltage. Resistor R6

limits LED current and sets overall control loop DC gain.

Diode D4 and C14 provide secondary soft-finish, feeding

current into the CONTROL pin prior to output regulation and

thus ensuring that the output voltage reaches regulation at start-

up under low line, full load conditions. Resistor R9 provides a

discharge path for C14. Capacitor C13 and R8 provide control

loop compensation and are required due to the gain associated

with such a high output voltage.

Sufficient heat sinking is required to keep the TOPSwitch-GX

device below 110 °C when operating under full load, low line

and maximum ambient temperature. Airflow may also be

required if a large heat sink area is not acceptable.

Figure 43. 250 W, 48 V Power Supply using TOP249.

48 V @ 5.2 A

+250 - 380 VDC

SXF

RTN

PI-2692-033001

All resistor 1/8 W 5% unless

otherwise stated.

CONTROL

TOPSwitch-GX

22 µF

400 V

0.1 µF

50 V

6.8 Ω

100 Ω

56 Ω

10 kΩ

47 µF

10 V

4.7 nF

1 kV

C13

150 nF

63 V

1 µF

50 V

C14

22 µF

63 V

560 µF

63 V

C10

560 µF

63 V

C11

560 µF

63 V

C12

68 µF

63 V

2.2 nF Y1

3 µH 8A

MUR1640CT

1N4148 U2

LTV817A

BYV26C

2 MΩ

1/2 W

68 kΩ

2 W

68 kΩ

2 W

VR1

P6KE200

VR2 22 V

BZX79B22

VR3 12 V

BZX79B12

VR4 12 V

BZX79B12

CONTROL

1N4148

PERFORMANCE SUMMARY

Output Power: 250 W

Line Regulation: ± 1%

Load Regulation: ± 5%

Efficiency: ≥ 85%

Ripple: < 100 mV pk-pk

No Load Consumption: ≤ 1.4 W (300 VDC)

TOP249Y

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Multiple Output, 60 W, 185-265 VAC Input Power Supply

Figure 44 shows a multiple output supply typical for high end

set-top boxes or cable decoders containing high capacity hard

disks for recording. The supply delivers an output power of

45 W cont./60 W peak (thermally limited) from an input

voltage of 185 to 265 VAC. Efficiency at 45 W, 185 VAC is

≥ 75%.

The 3.3 V and 5 V outputs are regulated to ±5% without the

need for secondary linear regulators. DC stacking (the

secondary winding reference for the other output voltages is

connected to the cathode of D10 rather than the anode) is used

to minimize the voltage error for the higher voltage outputs.

Due to the high ambient operating temperature requirement

typical of a set-top box (60 °C) the TOP246Y is used to

reduce conduction losses and minimize heat sink size. Resis-

tor R2 sets the device current limit to 80% of typical to limit

overload power. The line sense resistor (R1) protects the

TOPSwitch-GX from line surges and transients by sensing when

the DC rail voltage rises to above 450 V. In this condition the

TOPSwitch-GX stops switching, extending the input voltage

withstand to 496 VAC which is ideal for countries with poor

power quality. A thermistor (RT1) is used to prevent

premature failure of the fuse by limiting the inrush current (due

to the relatively large size of C2). An optional MOV (RV1)

extends the differential surge protection to 6 kV from 4 kV.

Leakage inductance clamping is provided by VR1, R5 and C5,

keeping the DRAIN voltage below 700 V under all conditions.

Resistor R5 and capacitor C5 are selected such that VR1

dissipates very little power except during overload conditions.

The frequency jittering feature of TOPSwitch-GX allows the

circuit shown to meet CISPR22B with simple EMI filtering

(C1, L1 and C6) and the output grounded.

The secondaries are rectified and smoothed by D7 to D1 1, C7,

C9, C11, C13, C14, C16 and C17. Diode D11 for the 3.3 V

output is a Schottky diode to maximize efficiency. Diode D10

for the 5 V output is a PN type to center the 5 V output at 5 V.

The 3.3 V and 5 V output require two capacitors in parallel to

meet the ripple current requirement. Switching noise filtering

is provided by L2 to L5 and C8, C10, C12, C15 and C18.

Resistor R6 prevents peak charging of the lightly loaded 30 V

output. The outputs are regulated using a secondary reference

(U3). Both the 3.3 V and 5 V outputs are sensed via R11 and

R10. Resistor R8 provides bias for U3 and R7 sets the overall

DC gain. Resistor R9, C19, R3 and C4 provide loop compen-

sation. A soft-finish capacitor (C20) eliminates output

overshoot.

Figure 44. 60 W Multiple Output Power Supply using TOP246.

1N4148

UF4003

UF5402

D11

MBR1045

D10

BYV32-200

T1 U2

LTV817

TL431

C20

22 µF

10 V

150 Ω

R12

10 k

C19

0.1 µF

R11

9.53

kΩ

R10

15.0

kΩ

3.3 kΩ

1 kΩ

2.2 nF

47 µF

50 V

330 µF

25 V

C11

390 µF

35 V

C14

1000 µF

25 V

30 V @

0.03 A

18 V @

0.5 A

12 V @

0.6 A

5 V @

3.2 A

3.3 V @

3 A

RTN

D1-D4

1N4007 V

3.15 A

RV1

275 V

14 mm

20 mH

0.8A

t°

6.8 Ω

47 µF

10 V

TOP246Y

TOPSwitch-GX

2 MΩ

1/2 W

68 kΩ

2 W

10 Ω

RT1

10 Ω

1.7 A

68 µF

400 V

1 nF

400 V

1 µF

50 V

0.1 µF

PI-2693-033001

CONTROL

0.1 µF

50 V

1N4937

VR1

P6KE170

C16

1000 µF

25 V

C13

1000 µF

25 V

C17

1000 µF

25 V

C15

220 µF

165 V

C18

220 µF

16 V

C12

100 µF

25 V

C10

100 µF

25 V

10 µF

50 V

3.3 µH

PERFORMANCE SUMMARY

Output Power: 45 W Cont./60 W Peak

Regulation:

3.3 V: ± 5%

5 V: ± 5%

12 V: ± 7%

18 V: ± 7%

30 V: ± 8%

Efficiency: ≥75%

No Load Consumption: 0.6 W

185-265 VAC

.R2

9.08 kΩ

TOP242-250

9/02

Processor Controlled Supply Turn On/Off

A low cost momentary contact switch can be used to turn the

TOPSwitch-GX power on and off under microprocessor

control that may be required in some applications such as

printers. The low power remote off feature allows an elegant

implementation of this function with very few external

components as shown in Figure 45. Whenever the push button

momentary contact switch P1 is closed by the user, the

optocoupler U3 is activated to inform the microprocessor of

this action. Initially, when the power supply is off (M pin is

floating), closing of P1 turns the power supply on by shorting

the M pin of the TOPSwitch-GX to SOURCE through a diode

(remote on). When the secondary output voltage VCC is

established, the microprocessor comes alive and recognizes that

the switch P1 is closed through the switch status input that is

driven by the optocoupler U3 output. The microprocessor then

sends a power supply control signal to hold the power supply

in the on-state through the optocoupler U4. If the user presses

the switch P1 again to command a turn off, the microprocessor

detects this through the optocoupler U3 and initiates a shut-

down procedure that is product specific. For example, in the

case of the inkjet printer , the shutdown procedure may include

safely parking the print heads in the storage position. In the

case of products with a disk drive, the shutdown procedure

may include saving data or settings to the disk. After the shut-

down procedure is complete, when it is safe to turn off the

power supply, the microprocessor releases the M pin by

turning the optocoupler U4 off. If the manual switch and the

optocouplers U3 and U4 are not located close to the M pin, a

capacitor CM may be needed to prevent noise coupling to the

pin when it is open.

The power supply could also be turned on remotely through a

local area network or a parallel or serial port by driving the

optocoupler U4 input LED with a logic signal. Sometimes it is

easier to send a train of logic pulses through a cable (due to AC

coupling of cable, for example) instead of a DC logic level as

a wake up signal. In this case, a simple RC filter can be used to

generate a DC level to drive U4 (not shown in Figure 45). This

remote on feature can be used to wake up peripherals such as

printers, scanners, external modems, disk drives, etc., as needed

from a computer. Peripherals are usually designed to turn off

automatically if they are not being used for a period of time, to

save power.

P1 Switch

Status

Power

Supply

ON/OFF

Control

External

Wake-up

Signal

PI-2561-033001

(+5 V)

RETURN

CONTROL

MICRO

PROCESSOR/

CONTROLLER

LOGIC

INPUT LOGIC

OUTPUT

High Voltage

DC Input

TOPSwitch-GX

1N4148

LTV817A

6.8 kΩ

1 nF

100 kΩ

6.8 kΩ

LTV817A

27 kΩ

1N4148

47 µF

Figure 45. Remote ON/OFF using Microcontroller.

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

In addition to using a minimum number of components,

TOPSwitch-GX provides many technical advantages in this type

of application:

1. Extremely low power consumption in the off mode: 80 mW

typical at 110 VAC and 160 mW typical at 230 VAC. This

is because in the remote/off mode the TOPSwitch-GX

consumes very little power, and the external circuitry does

not consume any current (either M, L or X pin is open) from

the high voltage DC input.

2. A very low cost, low voltage/current, momentary contact

switch can be used.

3. No debouncing circuitry for the momentary switch is required.

During turn-on, the start-up time of the power supply

(typically 10 to 20 ms) plus the microprocessor initiation

time act as a debouncing filter, allowing a turn-on only if the

switch is depressed firmly for at least the above delay time.

During turn-off, the microprocessor initiates the shutdown

sequence when it detects the first closure of the switch, and

subsequent bouncing of the switch has no effect. If necessary,

the microprocessor could implement the switch debouncing

in software during turn-off, or a filter capacitor can be used

at the switch status input.

4. No external current limiting circuitry is needed for the

operation of the U4 optocoupler output due to internal

limiting of M pin current.

5. No high voltage resistors to the input DC voltage rail are

required to power the external circuitry in the primary. Even

the LED current for U3 can be derived from the CONTROL

pin. This not only saves components and simplifies layout,

but also eliminates the power loss associated with the high

voltage resistors in both on and off states.

6. Robust design: There is no on/off latch that can be accidentally

triggered by transients. Instead, the power supply is held in

the on-state through the secondary side microprocessor.

TOP242-250

9/02

Key Application Considerations

TOPSwitch-II

vs.

TOPSwitch-GX

Table 4 compares the features and performance differences

between TOPSwitch-GX and TOPSwitch-II. Many of the new

features eliminate the need for additional discrete components.

Other features increase the robustness of design allowing cost

savings in the transformer and other power components.

Function

TOPSwitch-II

TOPSwitch-GX

Figures

TOPSwitch-GX

Advantages

Soft-Start N/A* 10 ms • Limits peak current and voltage

component stresses during start-up

•Eliminates external components

used for soft-start in most

applications

•Reduces or eliminates output

overshoot

External Current Limit N/A* Programmable 11,20,21, • Smaller transformer

100% to 30% of 24,25,27, • Higher efficiency

default current 28,34,35, • Allows power limiting (constant over-

limit 38,39 load power independent of line

voltage

•Allows use of larger device for lower

losses, higher efficiency and smaller

heatsink

DCMAX 67% 78% 7 • Smaller input cap (wider dynamic

range)

•Higher power capability (when used

with RCD clamp for large VOR)

•Allows use of Schottky secondary

rectifier diode for up to 15 V output

for high efficiency

Line Feed Forward with N/A* 78% to 38% 7,11,17, • Rejects line ripple

DCMAX Reduction 26,27,28,

31,40

Line OV Shutdown N/A* Single resistor 11,17,19, • Increases voltage withstand cap-

programmable 26,27,28, ability against line surge

31,33,40

Line UV Detection N/A* Single resistor 11,17,18, • Prevents auto-restart glitches

programmable 26,27,28, during power down

31,32,40

Switching Frequency 100 kHz ±10% 132 kHz ±6% 13,15 • Smaller transformer

•Below start of conducted EMI limits

Switching Frequency N/A* 66 kHz ±7% 14,15 • Lower losses when using RC and

Option (Y, R and F RCD snubber for noise reduction in

Packages) video applications

•Allows for higher efficiency in

standby mode

•Lower EMI (second harmonic below

150 kHz)

Frequency Jitter N/A* ±4 kHz@132 kHz 9,46 • Reduces conducted EMI

±2 kHz@66 kHz

Frequency Reduction N/A* At a Duty Cycle 7 • Zero load regulation without dummy

below 10% load

•Low power consumption at no load

Table 4. Comparison Between TOPSwitch-II and TOPSwitch-GX. (continued on next page) *Not available

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Table 4 (cont). Comparison Between TOPSwitch-II and TOPSwitch-GX. *Not available

Function

TOPSwitch-FX

TOPSwitch-GX TOPSwitch-GX

Advantages

Light Load Operation Cycle skipping Frequency and Duty Cycle • Improves light load efficiency

reduction • Reduces no-load consumption

Line Sensing/Externally Line sensing and Line sensing and externally • Additional design flexibility allows all

Set Current Limit externally set set current limit possible features to be used simultaneously

(Y, R and F Packages) current limit simultaneously

mutually (functions split onto

exclusive (M pin) L and X pins)

Current Limit 100-40% 100-30% • Minimizes transformer core size

Programming in highly continuous designs

Range

TOPSwitch-FX

vs.

TOPSwitch-GX

Table 5 compares the features and performance differences

between TOPSwitch-GX and TOPSwitch-FX. Many of the new

features eliminate the need for additional discrete components.

Other features increase the robustness of design allowing cost

savings in the transformer and other power components.

Function

TOPSwitch-II TOPSwitch-GX

Figures

TOPSwitch-GX

Advantages

Remote ON/OFF N/A* Single transistor 11, 22, • Fast on/off (cycle by cycle)

or optocoupler 23, 24, • Active-on or active-off control

interface or manual 25, 26, • Low consumption in remote off state

switch 27, 29, • Active-on control for fail-safe

36, 37, • Eliminates expensive in-line on/off

38, 39, switch

40 • Allows processor controlled turn

on/off

•Permits shutdown/wake-up of

peripherals via LAN or parallel port

Synchronization N/A* Single transistor • Synchronization to external lower

or optocoupler frequency signal

interface • Starts new switching cycle on

demand

Thermal Shutdown 125 °C min. Hysteretic 130 °C•Automatic recovery from thermal

Latched min. Shutdown (with fault

75 °C hysteresis) • Large hysteresis prevents circuit

board overheating

Current Limit Tolerance ±10% (@25 °C) ±7% (@25 °C) • 10% higher power capability due to

-8% (0 °C to100 °C) -4% (0 °C to 100 °C) tighter tolerance

DRAIN DIP 0.037" / 0.94 mm 0.137" / 3.48 mm • Greater immunity to arcing as a

Creepage SMD 0.037" / 0.94 mm 0.137" / 3.48 mm result of build-up of dust, debris and

at Package TO-220 0.046" / 1.17 mm 0.068" / 1.73 mm other contaminants

DRAIN Creepage at 0.045" / 1.14 mm 0.113" / 2.87 mm • Preformed leads accommodate

PCB for Y, R and F (R and F (preformed leads) large creepage for PCB layout

Packages Package N/A*) • Easier to meet Safety (UL/VDE)

Table 5. Comparison Between TOPSwitch-FX and TOPSwitch-GX. (continued on next page)

TOP242-250

9/02

Table 5 (cont). Comparison Between TOPSwitch-FX and TOPSwitch-GX. *Not available

TOPSwitch-GX

Design Considerations

Power Table

Data sheet power table (T able 1) represents the maximum practi-

cal continuous output power based on the following conditions:

TOP242 to T OP246: 12 V output, Schottky output diode, 150 V

reflected voltage (VOR) and efficiency estimates from curves con-

tained in application note AN-29. TOP247 to TOP250: Higher

output voltages, with a maximum output current of 6 A.

For all devices, a 100 VDC minimum for 85-265 VAC and

250 VDC minimum for 230 VAC are assumed and sufficient heat

sinking to keep device temperature ≤100 °C. Power

levels shown in the power table for the R package device

assume 6.45 cm2 of 610 g/m2 copper heat sink area in an

enclosed adapter, or 19.4 cm2 in an open frame.

TOPSwitch-GX Selection

Selecting the optimum TOPSwitch-GX depends upon required

maximum output power, efficiency, heat sinking constraints

and cost goals. With the option to externally reduce current

limit, a larger TOPSwitch-GX may be used for lower power

applications where higher efficiency is needed or minimal heat

sinking is available.

Function

TOPSwitch-FX

TOPSwitch-GX TOPSwitch-GX

Advantages

P/G Package Current Identical to Y TOP243P or G and • Matches device current limit to

Limits packages TOP244P or G internal package dissipation capability

current limits reduced • Allows more continuous design to

lower device dissipation (lower RMS

currents)

Y/R/F Package Current 100% (R and F 90% (for equivalent RDS (ON))•Minimizes transformer core size

Limits package N/A*) • Optimizes efficiency for most

applications

Thermal Shutdown 125 °C min. 130 °C min. 75 °C•Allows higher output powers in

70 °C hysteresis hysteresis high ambient temperature

applications

Maximum Duty Cycle 90 µA 60 µA•Reduces output line frequency

Reduction Threshold ripple at low line

•D

MAX reduction optimized for

forward design

Line Under-Voltage N/A* 40% of positive (turn-on) • Provides a well defined turn-off

Negative (turn-off) threshold threshold as the line voltage falls

Threshold

Soft-Start 10 ms (duty cycle) 10 ms (duty cycle + current • Gradually increasing current limit

limit) in addition to duty cycle during soft-

start further reduces peak current

and voltage

•Further reduces component

stresses during start up

Input Capacitor

The input capacitor must be chosen to provide the minimum DC

voltage required for the TOPSwitch-GX converter to maintain

regulation at the lowest specified input voltage and maximum

output power. Since TOPSwitch-GX has a higher DCMAX than

TOPSwitch-II, it is possible to use a smaller input capacitor.

For TOPSwitch-GX, a capacitance of 2 µF per watt is possible

for universal input with an appropriately designed transformer.

Primary Clamp and Output Reflected Voltage VOR

A primary clamp is necessary to limit the peak TOPSwitch-GX

drain to source voltage. A Zener clamp requires few parts and

takes up little board space. For good efficiency, the clamp

Zener should be selected to be at least 1.5 times the output

reflected voltage VOR as this keeps the leakage spike conduc-

tion time short. When using a Zener clamp in a universal input

application, a VOR of less than 135 V is recommended to allow

for the absolute tolerances and temperature variations of the

Zener . This will ensure ef ficient operation of the clamp circuit

and will also keep the maximum drain voltage below the rated

breakdown voltage of the TOPSwitch-GX MOSFET.

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Figure 46b. TOPSwitch-GX Full Range EMI Scan (132 kHz,

with jitter) with Identical Circuitry and

Conditions.

A high VOR is required to take full advantage of the wider DCMAX

of TOPSwitch-GX. An RCD clamp provides tighter clamp

voltage tolerance than a Zener clamp and allows a VOR as high as

150 V. RCD clamp dissipation can be minimized by reducing

the external current limit as a function of input line voltage (see

Figure 21 and 35). The RCD clamp is more cost effective than

the Zener clamp but requires more careful design (see quick

design checklist).

Output Diode

The output diode is selected for peak inverse voltage, output

current, and thermal conditions in the application (including

heatsinking, air circulation, etc.). The higher DCMAX of

TOPSwitch-GX along with an appropriate transformer turns ratio

can allow the use of a 60 V Schoktty diode for higher ef ficiency

on output voltages as high as 15 V (see Figure 41. A 12 V, 30 W

design using a 60 V Schottky for the output diode).

Bias Winding Capacitor

Due to the low frequency operation at no-load a 1 µF bias

winding capacitor is recommended.

Soft-Start

Generally a power supply experiences maximum stress at

start-up before the feedback loop achieves regulation. For a

period of 10 ms the on-chip soft-start linearly increases the duty

cycle from zero to the default DCMAX at turn on. In addition, the

primary current limit increases from 85% to 100% over the same

period. This causes the output voltage to rise in an orderly

manner allowing time for the feedback loop to take control of the

duty cycle. This reduces the stress on the TOPSwitch-GX

MOSFET, clamp circuit and output diode(s), and helps prevent

transformer saturation during start-up. Also soft-start limits the

amount of output voltage overshoot, and in many applications

eliminates the need for a soft-finish capacitor.

EMI

The frequency jitter feature modulates the switching frequency

over a narrow band as a means to reduce conducted EMI peaks

associated with the harmonics of the fundamental switching

frequency. This is particularly beneficial for average detection

mode. As can be seen in Figure 46, the benefits of jitter increase

with the order of the switching harmonic due to an increase in

frequency deviation.

The FREQUENCY pin of TOPSwitch-GX offers a switching

frequency option of 132 kHz or 66 kHz. In applications that

require heavy snubbers on the drain node for reducing high

frequency radiated noise (for example, video noise sensitive

applications such as VCR, DVD, monitor , TV, etc.), operating at

66 kHz will reduce snubber loss resulting in better efficiency.

Also, in applications where transformer size is not a concern, use

of the 66 kHz option will provide lower EMI and higher

efficiency. Note that the second harmonic of 66 kHz is still

below 150 kHz, above which the conducted EMI specifications

get much tighter.

For 10 W or below, it is possible to use a simple inductor in

place of a more costly AC input common mode choke to meet

worldwide conducted EMI limits.

Transformer Design

It is recommended that the transformer be designed for

maximum operating flux density of 3000 Gauss and a peak flux

density of 4200 Gauss at maximum current limit. The turns ratio

should be chosen for a reflected voltage (VOR) no greater than

135 V when using a Zener clamp, or 150 V (max) when using

RCD clamp with current limit reduction with line voltage

(overload protection).

For designs where operating current is significantly lower than

the default current limit, it is recommended to use an externally

set current limit close to the operating peak current to reduce

peak flux density and peak power (see Figures 20 and 34). In

most applications, the tighter current limit tolerance, higher

EN55022B (QP)

EN55022B (AV)

-20

-10

0.15 1 10 30

Frequency (MHz)

Amplitude (dBµV)

PI-2577-010600

TOPSwitch-GX

(with jitter)

Figure 46a. TOPSwitch-II Full Range EMI Scan

(100 kHz, no jitter).

-20

-10

0.15 1 10 30

Frequency (MHz)

Amplitude (dBµV)

PI-2576-010600

EN55022B (QP)

EN55022B (AV)

TOPSwitch-II

(no jitter)

TOP242-250

9/02

switching frequency and soft-start features of TOPSwitch-GX

contribute to a smaller transformer when compared to

TOPSwitch-II.

Standby Consumption

Frequency reduction can significantly reduce power loss at light

or no load, especially when a Zener clamp is used. For very

low secondary power consumption use a TL431 regulator for

feedback control. Alternately, switching losses can be

significantly reduced by changing from 132 kHz in normal

operation to 66 kHz under light load conditions.

TOPSwitch-GX

Layout Considerations

As TOPSwitch-GX has additional pins and operates at much

higher power levels compared to previous TOPSwitch

families, the following guidelines should be carefully

followed.

Primary Side Connections

Use a single point (Kelvin) connection at the negative terminal

of the input filter capacitor for TOPSwitch-GX source pin and

bias winding return. This improves surge capabilities by

returning surge currents from the bias winding directly to the

input filter capacitor.

The CONTROL pin bypass capacitor should be located as

close as possible to the SOURCE and CONTROL pins and its

SOURCE connection trace should not be shared by the main

MOSFET switching currents. All SOURCE pin referenced

components connected to the MULTI-FUNCTION, LINE-

SENSE or EXTERNAL CURRENT LIMIT pins should also

be located closely between their respective pin and SOURCE.

Once again the SOURCE connection trace of these

components should not be shared by the main MOSFET

switching currents. It is very critical that SOURCE pin

switching currents are returned to the input capacitor negative

terminal through a seperate trace that is not shared by the

components connected to CONTROL, MULTI-FUNCTION,

LINE-SENSE or EXTERNAL CURRENT LIMIT pins. This

is because the SOURCE pin is also the controller ground

reference pin.

Any traces to the M, L or X pins should be kept as short as

possible and away from the DRAIN trace to prevent noise

coupling. LINE-SENSE resistor (R1 in figures 47-49) should

be located close to the M or L pin to minimize the trace length

on the M or L pin side.

In addition to the 47 µF CONTROL pin capacitor, a high

frequency bypass capacitor in parallel may be used for better

noise immunity . The feedback optocoupler output should also

be located close to the CONTROL and SOURCE pins of

TOPSwitch-GX.

Y-Capacitor

The Y-capacitor should be connected close to the secondary

output return pin(s) and the positive primary DC input pin of

the transformer.

Heat Sinking

The tab of the Y package (TO-220) or F package (TO-262) is

internally electrically tied to the SOURCE pin. To avoid circu-

lating currents, a heat sink attached to the tab should not be

electrically tied to any primary ground/source nodes on the PC

board.

When using a P (DIP-8), G (SMD-8) or R (TO-263) package,

a copper area underneath the package connected to the

SOURCE pins will act as an effective heat sink. On double

sided boards (Figure 49), top side and bottom side areas

connected with vias can be used to increase the effective heat

sinking area.

In addition, sufficient copper area should be provided at the

anode and cathode leads of the output diode(s) for heat

sinking.

In Figures 47, 48 and 49 a narrow trace is shown between the

output rectifier and output filter capacitor. This trace acts as a

thermal relief between the rectifier and filter capacitor to

prevent excessive heating of the capacitor.

Quick Design Checklist

As with any power supply design, all TOPSwitch-GX designs

should be verified on the bench to make sure that components

specifications are not exceeded under worst case conditions.

The following minimum set of tests is strongly recommended:

1. Maximum drain voltage – Verify that peak VDS does not

exceed 675 V at highest input voltage and maximum over -

load output power. Maximum overload output power

occurs when the output is overloaded to a level just before

the power supply goes into auto-restart (loss of regulation).

2. Maximum drain current – At maximum ambient tempera-

ture, maximum input voltage and maximum output load,

verify drain current waveforms at start-up for any signs of

transformer saturation and excessive leading edge current

spikes. TOPSwitch-GX has a leading edge blanking time

of 220 ns to prevent premature termination of the on-cycle.

Verify that the leading edge current spike is below the

allowed current limit envelope (see Figure 52) for the drain

current waveform at the end of the 220 ns blanking period.

3. Thermal check – At maximum output power, minimum

input voltage and maximum ambient temperature, verify

that temperature specifications are not exceeded for

TOPSwitch-GX, transformer, output diodes and output

capacitors. Enough thermal margin should be allowed for

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Figure 47. Layout Considerations for TOPSwitch-GX using P or G Packages.

Figure 48. Layout Considerations for TOPSwitch-GX using Y or F Package.

Input Filter Capacitor

Heat Sink

Safety Spacing

Opto-

coupler +- DC

Out

Output Filter Capacitor

SEC

Maximize hatched copper

areas ( ) for optimum

heat sinking

Y1-

Capacitor

PI-2669-042301

TOP VIEW

TOPSwitch-GX

Output Rectifier

TOP VIEW

PI-2670-042301

Y1-

Capacitor

Opto-

coupler

R2 +- DC

Out

Input Filter Capacitor Output Filter Capacitor

Output Rectifier

Safety Spacing

Maximize hatched copper

areas ( ) for optimum

heat sinking

PRI

SEC

BIAS

TOPSwitch-GX

TOP242-250

9/02

the part-to-part variation of the RDS(ON) of TOPSwitch-GX

as specified in the data sheet. The margin required can

either be calculated from the tolerances or it can be

accounted for by connecting an external resistance in

series with the DRAIN pin and attached to the same

heatsink, having a resistance value that is equal to the

difference between the measured RDS(ON) of the device

under test and the worst case maximum specification.

Figure 49. Layout Considerations for TOPSwitch-GX using R Package.

+- DC

Out

PI-2734-043001

Safety Spacing

Y1-

Capacitor

Solder Side

Component Side

Opto-

coupler

Output Filter Capacitors

Maximize hatched copper

areas( ) for optimum

heat sinking

TOP VIEW

Input Filter

Capacitor

R1a - 1c

PRI

PRI SEC

BIAS

TOPSwitch-GX

Design Tools

For a discussion on utilizing TOPSwitch-GX in a forward

converter configuration, please r efer to the TOPSwitch-GX

Forward Design Methodology Application Note.

Up-to-date information on design tools can be found at the

Power Integrations Web site: www.powerint.com

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

ABSOLUTE MAXIMUM RATINGS(1)

DRAIN Voltage ............................................ -0.3 to 700 V

DRAIN Peak Current: TOP242 ...............................0.72 A

TOP243 ...............................1.44 A

TOP244 ...............................2.16 A

TOP245 ...............................2.88 A

TOP246 ...............................4.32 A

TOP247 ...............................5.76 A

TOP248 ...............................7.20 A

TOP249 ...............................8.64 A

TOP250 .............................10.08 A

CONTROL Voltage .......................................... -0.3 to 9 V

IC = 3 mA;

TJ = 25 °C

IC = ICD1

fOSC

DC(ONSET)

fOSC (DMIN)

∆f

DCMAX

CONTROL FUNCTIONS

Conditions

(Unless Otherwise Specified)

See Figure 53

SOURCE = 0 V; TJ = -40 to 125 °C

Min Typ Max

Parameter Symbol Units

THERMAL IMPEDANCE

kHz

Thermal Impedance: Y or F Package:

(θJA) (1) ....................................... 70 °C/W

(θJC) (2) ......................................... 2 °C/W

P or G Package:

(θJA) ......................45 °C/W(3); 35 °C/W(4)

(θJC) (5) ....................................... 11 °C/W

R Package:

(θJA) ... 80 °C/W(7); 37 °C/W(4); 27 °C/W(6)

(θJC) (5) ......................................... 2 °C/W

Notes:

1. Free standing with no heatsink.

2. Measured at the back surface of tab.

3. Soldered to 0.36 sq. inch (232 mm2), 2 oz. (610 gm/m2) copper clad.

4. Soldered to 1 sq. inch (645 mm2), 2 oz. (610 gm/m2) copper clad.

5. Measured on the SOURCE pin close to plastic interface.

6. Soldered to 3 sq. inch (1935 mm2), 2 oz. (610 gm/m2) copper

clad.

7. Soldered to foot print area, 2 oz. (610 gm/m2) copper clad.

124 132 140

61.5 66 70.5

± 4

± 2

250

75 78 83

28 38 50

FREQUENCY Pin

Connected to SOURCE

FREQUENCY Pin

Connected to CONTROL

132 kHz Operation

66 kHz Operation

IL ≤ IL (DC) or IM ≤ IM(DC)

IL or IM = 190 µA

Switching

Frequency

(average)

Duty Cycle at

ONSET of Fre-

quency Reduction

Switching

Frequency near

0% Duty Cycle

Frequency Jitter

Deviation

Frequency Jitter

Modulation Rate

Maximum Duty

Cycle

132 kHz Operation

66 kHz Operation

CONTROL Current ...............................................100 mA

LINE SENSE Pin Voltage ................................ -0.3 to 9 V

CURRENT LIMIT Pin Voltage..................... -0.3 to 4.5 V

MULTI-FUNCTION Pin Voltage .................... -0.3 to 9 V

FREQUENCY Pin Voltage............................... -0.3 to 9 V

Storage Temperature ..................................... -65 to 150 °C

Operating Junction Temperature (2) ...............-40 to 150 °C

Lead Temperature (3) ............................................... 260 °C

Notes:

1. All voltages referenced to SOURCE, TA = 25 °C.

2. Normally limited by internal circuitry.

3. 1/16" from case for 5 seconds.

TOP242-250

9/02

CONTROL FUNCTIONS

Conditions

(Unless Otherwise Specified)

See Figure 53

SOURCE = 0 V; TJ = -40 to 125 °C

Min Typ Max

Parameter Symbol Units

See Note A

See Figure 7

TJ = 25 °C

IC = 4 mA; TJ = 25 °C

See Figure 51

lC(OFF)

PWM Gain

Temperature Drift

External Bias

Current

CONTROL

Current at 0%

Duty Cycle

Dynamic

Impedance

Dynamic

Impedance

Temperature Drift

Control Pin

Internal Filter Pole

%/mA/°C

Ω

%/°C

kHz

SHUTDOWN/AUTO-RESTART

VC = 0 V

VC = 5 V

lC (CH)

VC(AR)U

VC(AR)L

VC(AR)hyst

DC(AR)

f(AR)

Control Pin

Charging Current

Temperature Drift

Auto-restart Upper

Threshold Voltage

Auto-restart Lower

Threshold Voltage

Auto-restart

Hysteresis Voltage

Auto-restart Duty

Cycle

Auto-restart

Frequency

%/°C

-5.0 -3.5 -2.0

-3.0 -1.8 -0.6

0.5

5.8

4.5 4.8 5.1

0.8 1.0

1.0

TJ = 25 °C

See Note A

Soft Start Time tSOFT TJ = 25 °C; DCMIN to DCMAX 10 15 ms

PWM Gain DCreg IC = 4 mA; TJ = 25 °C -28 -23 -18 %/mA

TOP242-245

TOP246-249

TOP250

TOP242-245

TOP246-249

TOP250

-0.01

1.2 2.0 3.0

1.6 2.6 4.0

1.7 2.7 4.2

6.0 7.0

6.6 8.0

7.3 8.5

10 15 22

0.18

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Conditions

(Unless Otherwise Specified)

See Figure 53

SOURCE = 0 V; TJ = -40 to 125 °C

Min Typ Max

Parameter Symbol Units

µA

%/µA

44 50 54

210 225 240

0.5 1.0 1.6

-35 -27 -20

300 400 520

-300 -240 -180

-110 -90 -70

1.90 2.50 3.00

2.30 2.90 3.30

1.26 1.33 1.40

1.18 1.24 1.30

1.24 1.31 1.39

1.13 1.19 1.25

40 60 75

0.25

0.6 1.0

1.0 1.6

TJ = 25 °C

Threshold

Hysteresis

TJ = 25 °C

Threshold

Hysteresis

Line Under-Voltage

Threshold Current

and Hysteresis

(M or L Pin)

Line Over-Voltage

or Remote ON/

OFF Threshold

Current and Hys-

teresis (M o r L Pin)

L Pin Voltage

Threshold

Remote ON/OFF

Negative Threshold

Current and Hyster-

esis (M or X Pin)

L or M Pin Short

Circuit Current

X or M Pin Short

Circuit Current

L or M Pin Voltage

(Positive Current)

X Pin Voltage

(Negative Current)

M Pin Voltage

(Negative Current)

Maximum Duty

Cycle Reduction

Onset Threshold

Current

Maximum Duty

Cycle Reduction

Slope

Remote OFF

DRAIN Supply

Current

Threshold

Hysteresis

MULTI-FUNCTION (M), LINE-SENSE (L) AND EXTERNAL CURRENT LIMIT (X) INPUTS

L or M Pin Shorted

to CONTROL

VL, VM = VC

Normal Mode

Auto-restart Mode

lL or lM = 50 µA

lL or lM = 225 µA

lX = -50 µA

lX = -150 µA

lM = -50 µA

lM = -150 µA

lUV

IOV

VL(TH)

IREM (N)

IL (SC) or

IM (SC)

IX (SC) or

IM (SC)

VL, VM

IL (DC) or

IM (DC)

ID(RMT)

VX, VM = 0 V

X, L or M Pin

Floating

TJ = 25 °C

IL > IL(DC) or IM > IM (DC)

See Figure 70

VDRAIN = 150 V

TJ = 25 °C

TOP242-250

9/02

ILIMIT

IINIT

Conditions

(Unless Otherwise Specified)

See Figure 53

SOURCE = 0 V; TJ = -40 to 125 °C

Min Typ Max

Parameter Symbol Units

CIRCUIT PROTECTION

FREQUENCY INPUT

FREQUENCY Pin

Threshold Voltage

FREQUENCY Pin

Input Current VF = VC

Self Protection

Current Limit

(See Note C)

Initial Current Limit

See Note B 2.9 V

10 40 100 µA

MULTI-FUNCTION (M), LINE-SENSE (L) AND EXTERNAL CURRENT LIMIT (X) INPUTS

Remote ON Delay

Remote OFF

Setup Time

tR(ON)

tR(OFF)

From Remote On to Drain Turn-On

See Note B

Minimum Time Before Drain Turn-On

to Disable Cycle

See Note B

2.5 µs

TOP242 P/G

TOP242 Y/R/F

TJ= 25 °C

TOP243 P/G

TJ= 25 °C

TOP243 Y/R/F

TJ= 25 °C

TOP244 P/G

TJ= 25 °C

TOP244 Y/R/F

TJ= 25 °C

TOP245 Y/R/F

TJ= 25 °C

TOP246 Y/R/F

TJ= 25 °C

TOP247 Y/R/F

TJ= 25 °C

TOP248 Y/R/F

TJ= 25 °C

TOP249 Y/R/F

TJ= 25 °C

TOP250 Y/R/F

TJ= 25 °C

≤ 85 VAC

(Rectified Line Input)

265 VAC

(Rectified Line Input)

Internal

di/dt=90 mA/µs

Internal

di/dt=150 mA/µs

Internal

di/dt=180 mA/µs

Internal

di/dt=200 mA/µs

Internal

di/dt=270 mA/µs

Internal

di/dt=360 mA/µs

Internal

di/dt=540 mA/µs

Internal

di/dt=720 mA/µs

Internal

di/dt=900 mA/µs

Internal

di/dt=1080 mA/µs

Internal

di/dt=1260 mA/µs

0.418 0.45 0.481

0.697 0.75 0.802

0.837 0.90 0.963

0.930 1.00 1.070

1.256 1.35 1.445

1.674 1.80 1.926

2.511 2.70 2.889

3.348 3.60 3.852

4.185 4.50 4.815

5.022 5.40 5.778

5.859 6.30 6.741

0.75 x

ILIMIT(MIN)

0.6 x

ILIMIT(MIN)

See

Note B

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Conditions

(Unless Otherwise Specified)

See Figure 53

SOURCE = 0 V; TJ = -40 to 125 °C

Min Typ Max

Parameter Symbol Units

OUTPUT

CIRCUIT PROTECTION

tIL(D)

VC(RESET)

100

130 140 150

1.75 3.0 4.25

°C

Current Limit Delay

Thermal Shutdown

Temperature

Thermal Shutdown

Hysteresis

Power-up Reset

Threshold Voltage

IC = 4 mA

Figure 53, S1 Open

RDS(ON)

ON-State

Resistance

TJ = 25 °C

TJ = 100 °C

TJ = 25 °C

TJ = 100 °C

TJ = 25 °C

TJ = 100 °C

TJ = 25 °C

TJ = 100 °C

TJ = 25 °C

TJ = 100 °C

TJ = 25 °C

TJ = 100 °C

TJ = 25 °C

TJ = 100 °C

TJ = 25 °C

TJ = 100 °C

TJ = 25 °C

TJ = 100 °C

TOP242

ID = 50 mA

TOP243

ID = 100 mA

TOP244

ID = 150 mA

TOP245

ID = 200 mA

TOP246

ID = 300 mA

TOP247

ID = 400 mA

TOP248

ID = 500 mA

TOP249

ID = 600 mA

TOP250

ID = 700 mA

15.6 18.0

25.7 30.0

7.80 9.00

12.9 15.0

5.20 6.00

8.60 10.0

3.90 4.50

6.45 7.50

2.60 3.00

4.30 5.00

1.95 2.25

3.22 3.75

1.56 1.80

2.58 3.00

1.30 1.50

2.15 2.50

1.10 1.28

1.85 2.15

Ω

Off-State

Current

Breakdown

Voltage

IDSS

BVDSS

470 µA

700 V

VL, VM = Floating; IC = 4 mA

VDS = 560 V; TJ = 125 °C

VL, VM = Floating; IC = 4mA

See Note D, TJ = 25 °C

Leading Edge

Blanking Time tLEB 220 ns

See Figure 52

TJ = 25 °C, IC = 4 mA

TOP242-250

9/02

Conditions

(Unless Otherwise Specified)

See Figure 53

SOURCE = 0 V; TJ = -40 to 125 °C

Min Typ Max

Parameter Symbol Units

SUPPLY VOLTAGE CHARACTERISTICS

5.60 5.85 6.10

±50

1.0 1.6 2.5

1.2 2.2 3.2

1.3 2.4 3.65

0.3 0.6 1.3

ppm/°C

VC(SHUNT)

lCD1

lCD2

See Note E

IC = 4 mA

Output

MOSFET Disabled

VX, VL, VM = 0 V

NOTES:

A. For specifications with negative values, a negative temperature coefficient corresponds to an increase in

magnitude with increasing temperature, and a positive temperature coefficient corresponds to a decrease in

magnitude with increasing temperature.

B. Guaranteed by characterization. Not tested in production.

C.For externally adjusted current limit values, please refer to Figure 55 (Current Limit vs. External Current Limit

Resistance) in the Typical Performance Characteristics section.

D.Breakdown voltage may be checked against minimum BVDSS specification by ramping the DRAIN pin voltage up to

but not exceeding minimum BVDSS.

E. It is possible to start up and operate

TOPSwitch-GX

at DRAIN voltages well below 36 V. However, the

CONTROL pin charging current is reduced, which affects start-up time, auto-restart frequency, and auto-restart

duty cycle. Refer to Figure 67, the characteristic graph on CONTROL pin charge current (IC) vs. DRAIN voltage

for low voltage operation characteristics.

DRAIN Supply

Voltage

Shunt Regulator

Voltage

Shunt Regulator

Temperature Drift

Control Supply/

Discharge Current

Output

MOSFET Enabled

VX, VL, VM = 0 V

TOP242-245

TOP246-249

TOP250

OUTPUT

Rise Time

Fall Time

Measured in a Typical

Flyback Converter Application

100 ns

50 ns

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Figure 51. CONTROL Pin I-V Characteristic.

Figure 50. Duty Cycle Measurement.

Figure 52. Drain Current Operating Envelope.

Figure 53. TOPSwitch-GX General Test Circuit.

PI-2631-010802

5-50 V 5-50 V

40 V

0-15 V 0.1 µF47 µF

470 Ω

5 W

Y, R or F Package (X and L Pin) P or G Package (M Pin)

470 Ω

0-100 kΩ

0-60 kΩ

0-100 kΩ

NOTES: 1. This test circuit is not applicable for current limit or output characteristic measurements.

2. For P and G packages, short all SOURCE pins together.

SFX

CONTROL

TOPSwitch-GX

PI-2039-033001

DRAIN

VOLTAGE

0 V

90%

10%

90%

D = t1

0.8

1.3

1.2

1.1

0.9

0.8

1.0

0012 6 83

Time (µs)

DRAIN Current (normalized)

PI-2022-033001

45 7

0.7

0.6

0.5

0.4

0.3

0.2

0.1

ILIMIT(MAX) @ 25 °C

ILIMIT(MIN) @ 25 °C

IINIT(MIN) @ 85 VAC

IINIT(MIN) @ 265 VAC

tLEB (Blanking Time)

120

100

00246810

CONTROL Pin Voltage (V)

CONTROL Pin Current (mA)

Slope

Dynamic

Impedance =

PI-1939-091996

TOP242-250

9/02

The following precautions should be followed when testing

TOPSwitch-GX by itself outside of a power supply. The sche-

matic shown in Figure 53 is suggested for laboratory testing of

TOPSwitch-GX.

When the DRAIN pin supply is turned on, the part will be in

the auto-restart mode. The CONTROL pin voltage will be

oscillating at a low frequency between 4.8 and 5.8 V and the

drain is turned on every eighth cycle of the CONTROL pin

oscillation. If the CONTROL pin power supply is turned on

BENCH TEST PRECAUTIONS FOR EVALUATION OF ELECTRICAL CHARACTERISTICS

Typical Performance Characteristics

while in this auto-restart mode, there is only a 12.5% chance

that the CONTROL pin oscillation will be in the correct state

(drain active state) so that the continuous drain voltage wave-

form may be observed. It is recommended that the VC power

supply be turned on first and the DRAIN pin power supply

second if continuous drain voltage waveforms are to be

observed. The 12.5% chance of being in the correct state is

due to the divide-by-8 counter. Temporarily shorting the

CONTROL pin to the SOURCE pin will reset TOPSwitch-GX,

which then will come up in the correct state.

Figure 54. Current Limit vs. MULTI-FUNCTION Pin Current.

Figure 55. Current Limit vs. External Current Limit Resistance.

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

100

120

140

160

180

200

-250 -200 -150 -100 -50

(µA)

Current Limit (A)

di/dt (mA/µs)

PI-2653-010802

Scaling Factors:

TOP242: .45

TOP243 P/G: .75

TOP243 Y/R/F: .90

TOP244 P/G: 1

TOP244 Y/R/F: 1.35

TOP245: 1.80

TOP246: 2.70

TOP247: 3.60

TOP248: 4.50

TOP249: 5.40

TOP250: 6.32

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

100

120

140

160

180

200

05K10K 15K 20K 25K 30K 35K 40K

External Current Limit Resistor RIL (Ω)

Current Limit (A)

di/dt (mA/µs)

PI-2652-010802

45K

Scaling Factors:

TOP242: .45

TOP243 P/G: .75

TOP243 Y/R/F: .90

TOP244 P/G: 1

TOP244 Y/R/F: 1.35

TOP245: 1.80

TOP246: 2.70

TOP247: 3.60

TOP248: 4.50

TOP249: 5.40

TOP250: 6.32

Maximum and minimum levels

are based on characterization.

Minimum

Typical

Maximum

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Typical Performance Characteristics (cont.)

Figure 56. Breakdown Voltage vs. Temperature. Figure 57. Frequency vs. Temperature.

Figure 58. Internal Current Limit vs. Temperature. Figure 59. External Current Limit vs. Temperature

with RIL =12 k

Ω

Figure 60. Overvoltage Threshold vs. Temperature. Figure 61. Under-Voltage Threshold vs. Temperature.

1.1

1.0

0.9 -50 -25 0 25 50 75 100 125 150

Junction Temperature (°C)

Breakdown Voltage

(Normalized to 25 °C)

PI-176B-033001

1.2

1.0

0.8

0.6

0.4

0.2

-50 -25 0 25 50 75 100 125 150

Junction Temperature (°C)

PI-1123A-033001

Output Frequency

(Normalized to 25 °C)

1.2

1.0

0.8

0.6

0.4

0.2

0-50 -25 0 25 50 75 100 125 150

Junction Temperature (°C)

PI-2555-033001

Current Limit

(Normalized to 25 °C)

1.2

1.0

0.8

0.6

0.4

0.2

0-50 -25 0 25 50 75 100 125 150

Junction Temperature (°C)

PI-2554-033001

Current Limit

(Normalized to 25 °C)

1.2

1.0

0.8

0.6

0.4

0.2

0-50 -25 0 25 50 75 100 125 150

Junction Temperature (°C)

PI-2553-033001

Overvoltage Threshold

(Normalized to 25 °C)

1.2

1.0

0.8

0.6

0.4

0.2

0-50 -25 0 25 50 75 100 125 150

Junction Temperature (°C)

PI-2552-033001

Under-Voltage Threshold

(Normalized to 25 °C)

TOP242-250

9/02

Typical Performance Characteristics (cont.)

0-300 -200 -100 0 100 200 300 400 500

PI-2542-102700

MULTI-FUNCTION Pin Voltage (V)

MULTI-FUNCTION Pin Current (µA)

See

Expanded

Version

Figure 63a. MULTI-FUNCTION Pin Voltage vs. Current. Figure 63b. MULTI-FUNCTION Pin Voltage vs.

Current (Expanded).

Figure 64. Control Current Out at 0% Duty Cycle vs.

Temperature. Figure 65. Max. Duty Cycle Reduction Onset Threshold

Current vs. Temperature.

6.0

4.5

5.5

5.0

2.0 0100 200 300 400

LINE-SENSE Pin Current (µA)

LINE SENSE Pin Voltage (V)

PI-2688-102700

3.0

2.5

3.5

4.0

Figure 62a. LINE-SENSE Pin Voltage vs. Current. Figure 62b. EXTERNAL CURRENT LIMIT Pin Voltage

vs. Current.

1.2

1.0

0.8

0.6

0.4

0.2

0-50 -25 0 25 50 75 100 125 150

Junction Temperature (°C)

PI-2562-033001

CONTROL Current

(Normalized to 25 °C)

1.2

1.0

0.8

0.6

0.4

0.2

0-50 -25 0 25 50 75 100 125 150

Junction Temperature (°C)

PI-2563-033001

Onset Threshold Current

(Normalized to 25 °C)

1.6

1.0

1.4

1.2

0-240 -180 -60-120 0

EXTERNAL CURRENT LIMIT Pin Current (µA)

EXTERNAL CURRENT LIMIT

Pin Voltage (V)

PI-2689-102300

0.4

0.2

0.6

0.8

= 1.33 - I

x 0.66 kΩ

-200 µA

≤

-25 µA

1.2

1.4

1.6

0.4

0.6

0.2

0.8

1.0

0-300 -200 -150 -50-250 -100 0

MULTI-FUNCTION Pin Voltage (V)

PI-2541-102700

MULTI-FUNCTION Pin Current (µA)

VM = 1.37 - IMx 1 kΩ

-200 µA ≤ IM ≤ -25 µA

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Typical Performance Characteristics (cont.)

0 100 200 300 400 500 600

100

1000

10000

PI-2646-010802

Drain Voltage (V)

DRAIN Capacitance (pF)

TOP250 1.17

TOP249 1.00

TOP248 0.83

TOP247 0.67

TOP246 0.50

TOP245 0.33

TOP244 0.25

TOP243 0.17

TOP242 0.08

Scaling Factors:

600

400

500

200

100

300

00200100 400 500300 600

DRAIN Voltage (V)

Power (mW)

PI-2650-020802

TOP250 1.17

TOP249 1.00

TOP248 0.83

TOP247 0.67

TOP246 0.50

TOP245 0.33

TOP244 0.25

TOP243 0.17

TOP242 0.08

Scaling Factors:

Figure 68. COSS vs. DRAIN Voltage.

Figure 66. Output Characteristics.

1.2

0.8

1.0

-50 050100 150

Junction Temperature (°C)

Remote OFF DRAIN Supply Current

(Normalized to 25 °C)

PI-2690-102700

0.2

0.4

0.6

Figure 70. Remote OFF DRAIN Supply Current

vs. Temperature.

0024681012 14 16 18 20

DRAIN Voltage (V)

DRAIN Current (A)

PI-2645-010802

1TCASE = 25 °C

TCASE = 100 °C

3TOP250 1.17

TOP249 1.00

TOP248 0.83

TOP247 0.67

TOP246 0.50

TOP245 0.33

TOP244 0.25

TOP243 0.17

TOP242 0.08

Scaling Factors:

Figure 67. IC vs. DRAIN Voltage.

Figure 69. DRAIN Capacitance Power.

1.2

1.6

0020406080100

DRAIN Voltage (V)

CONTROL Pin

Charging Current (mA)

PI-2564-101499

0.4

0.8

VC = 5 V

TOP242-250

9/02

TOPSwitch

Product Family

GX Series Number

Package Identifier

G Plastic Surface Mount DIP

P Plastic DIP

Y Plastic TO-220-7C

R Plastic TO-263-7C (available only with TL option)

F Plastic TO-262

Package/Lead Options

Blank Standard Configurations

TL Tape & Reel, (G Package: 1000 min., R Package: 750 min.)

PART ORDERING INFORMATION

TOP 242 G - TL

(242, 243 & 244 only)

PI-2644-040501

Notes:

1. Controlling dimensions are inches. Millimeter

dimensions are shown in parentheses.

2. Pin numbers start with Pin 1, and continue

from left to right when viewed from the front.

3. Dimensions do not include mold flash or

other protrusions. Mold flash or protrusions

shall not exceed .006 (.15mm) on any side.

4. Minimum metal to metal spacing at the pack-

age body for omitted pin locations is .068

inch (1.73 mm).

5. Position of terminals to be measured at a

location .25 (6.35) below the package body.

6. All terminals are solder plated.

Y07C

PIN 1 PIN 7

MOUNTING HOLE PATTERN

.050 (1.27)

.150 (3.81)

.050 (1.27)

.150 (3.81)

.050 (1.27)

.100 (2.54)

.180 (4.58)

.200 (5.08)

PIN 1

.010 (.25) M

.467 (11.86)

.487 (12.37)

.400 (10.16)

.415 (10.54)

.146 (3.71)

.156 (3.96)

.860 (21.84)

.880 (22.35)

.026 (.66)

.032 (.81)

.050 (1.27) BSC

.150 (3.81) BSC

.108 (2.74) REF

PIN 1 & 7

7° TYP.

PIN 2 & 4

.040 (1.02)

.060 (1.52)

.190 (4.83)

.210 (5.33)

.015 (.38)

.020 (.51)

.095 (2.41)

.115 (2.92)

.236 (5.99)

.260 (6.60)

.165 (4.19)

.185 (4.70)

.040 (1.02)

.060 (1.52)

.045 (1.14)

.055 (1.40)

.670 (17.02)

REF.

.570 (14.48)

REF.

TO-220-7C

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Notes:

1. Package dimensions conform to JEDEC specification

MS-001-AB (Issue B 7/85) for standard dual-in-line (DIP)

package with .300 inch row spacing.

2. Controlling dimensions are inches. Millimeter sizes are

shown in parentheses.

3. Dimensions shown do not include mold flash or other

protrusions. Mold flash or protrusions shall not exceed

.006 (.15) on any side.

4. Pin locations start with Pin 1, and continue counter-clock-

wise to Pin 8 when viewed from the top. The notch and/or

dimple are aids in locating Pin 1. Pin 6 is omitted.

5. Minimum metal to metal spacing at the package body for

the omitted lead location is .137 inch (3.48 mm).

6. Lead width measured at package body.

7. Lead spacing measured with the leads constrained to be

perpendicular to plane T.

.008 (.20)

.015 (.38)

.300 (7.62) BSC

(NOTE 7)

.300 (7.62)

.390 (9.91)

.367 (9.32)

.387 (9.83)

.240 (6.10)

.260 (6.60)

.125 (3.18)

.145 (3.68)

.057 (1.45)

.068 (1.73)

.120 (3.05)

.140 (3.56)

.015 (.38)

MINIMUM

.050 (1.27)

.065 (1.65)

.100 (2.54) BSC

.014 (.36)

.022 (.56)

-E-

Pin 1

SEATING

PLANE

-D-

-T-

P08B

DIP-8B

PI-2551-101102

D S .004 (.10)

⊕

T E D S .010 (.25) M

⊕

(NOTE 6)

SMD-8B

PI-2546-101102

.004 (.10)

.012 (.30) .036 (0.91)

.044 (1.12)

.004 (.10) 0 -

° 8°

.367 (9.32)

.387 (9.83)

.048 (1.22) .009 (.23)

.065 (1.65)

.032 (.81)

.037 (.94)

.125 (3.18)

.145 (3.68)

-D-

Notes:

1. Controlling dimensions are

inches. Millimeter sizes are

shown in parentheses.

2. Dimensions shown do not

include mold flash or other

protrusions. Mold flash or

protrusions shall not exceed

.006 (.15) on any side.

3. Pin locations start with Pin 1,

and continue counter-clock

Pin 8 when viewed from the

top. Pin 6 is omitted.

4. Minimum metal to metal

spacing at the package body

for the omitted lead location

is .137 inch (3.48 mm).

5. Lead width measured at

package body.

6. D and E are referenced

datums on the package

body.

.057 (1.45)

.068 (1.73)

(NOTE 5)

E S

.100 (2.54) (BSC)

.372 (9.45)

.240 (6.10) .388 (9.86)

.260 (6.60) .010 (.25)

-E-

Pin 1

D S .004 (.10)

⊕

G08B

.420

.046 .060 .060 .046

.080

Pin 1

.086

.186

.286

Solder Pad Dimensions

TOP242-250

9/02

.165 (4.19)

.185 (4.70)

R07C

TO-263-7C

PI-2664-040501

-A-

LD #1

.580 (14.73)

.620 (15.75)

.396 (10.06)

.415 (10.54)

.326 (8.28)

.336 (8.53)

.055 (1.40)

.066 (1.68)

.100 (2.54)

Ref.

.208 (5.28)

Ref.

.026 (0.66)

.032 (0.81)

.225 (5.72)

min.

.245 (6.22)

min.

.000 (0.00)

.010 (0.25)

.090 (2.29)

.110 (2.79)

.017 (0.43)

.023 (0.58)

°8 -°0

.045 (1.14)

.055 (1.40)

.050 (1.27)

Notes:

1. Package Outline Exclusive of Mold Flash & Metal Burr.

2. Package Outline Inclusive of Plating Thickness.

3. Foot Length Measured at Intercept Point Between

Datum A Lead Surface.

4. Controlling Dimensions are in Inches. Millimeter

Dimensions are shown in Parentheses.

.004 (0.10)

.315 (8.00)

.128 (3.25)

.038 (0.97)

.050 (1.27)

.380 (9.65)

.638 (16.21)

Solder Pad

Dimensions

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

PI-2757-091702

Notes:

1. Controlling dimensions are inches. Millimeter

dimensions are shown in parentheses.

2. Pin numbers start with Pin 1, and continue

from left to right when viewed from the front.

3. Dimensions do not include mold flash or

other protrusions. Mold flash or protrusions

shall not exceed .006 (.15mm) on any side.

4. Minimum metal to metal spacing at the pack-

age body for omitted pin locations is .068

inch (1.73 mm).

5. Position of terminals to be measured at a

location .25 (6.35) below the package body.

6. All terminals are solder plated.

F07C

PIN 1 PIN 7

MOUNTING HOLE PATTERN

.050 (1.27)

.150 (3.81)

.050 (1.27)

.150 (3.81)

.050 (1.27)

.100 (2.54)

.180 (4.58)

.200 (5.08)

PIN 1

.010 (.25) M

.326 - .336

.396 - .415

.795 (20.18)

REF.

.026 (.66)

.032 (.81)

.050 (1.27) BSC

.150 (3.81) BSC

.055 - .066

PIN 1 & 7

7° TYP.

PIN 2 & 4

.040 (1.06)

.060 (1.52)

.190 (4.83)

.210 (5.33)

.015 (.38)

.020 (.51)

.095 (2.41)

.115 (2.92)

.165 (4.17)

.185 (4.70)

.040 (1.02)

.060 (1.52)

.045 (1.14)

.055 (1.40)

.595 (15.10)

REF.

.495 (12.56)

REF.

TO-262-7C

TOP242-250

9/02

Notes

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Notes

TOP242-250

9/02

Notes

TOP242-250

9/02

General Information & Table of Contents

Product Selector Guide 1

Data Sheets 2

Application Notes 3

Design Ideas 4

Design Tools 5

Quality and Reliability 6

Package Information 7

DPA-Switch

DC-DC Seminar 8

LinkSwitch

TinySwitch-II

AC-DC Seminar 9

TOPSwitch-GX

AC-DC Seminar 10

Sales Representatives and Distributors 11

Notes

1) Added R package (D2PAK).

2) Corrected abbreviations (s = seconds).

3) Corrected x-axis units in Figure 11 (µA).

4) Added missing external current limit resistor in Figure 25 (RIL).

5) Corrected spelling.

6) Added caption for Table 4.

7) Corrected Breakdown Voltage parameter condition (TJ = 25 °C).

8) Corrected font sizes in figures.

9) Figure 40 replaced.

10) Corrected schematic component values in Figure 44.

1) Corrected Power Table value.

1) Added TOP250 device and F package (TO-262).

2) Added R package Thermal Impedance parameters and adjusted Output Power values in Table 1.

3) Adjusted Off-State Current value.

1) Added note to parameter table for Breakdown Voltage measurement.

2) Miscellaneous text corrections.

Date

11/00

7/01

9/01

1/02

9/02

Revision

For the latest updates, visit our Web site: www.powerint.com

Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability.

Power Integrations does not assume any liability arising from the use of any device or circuit described herein, nor does it

convey any license under its patent rights or the rights of others. The products and applications illustrated herein may be

covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign patent applications assigned to

Power Integrations. A complete list of Power Integrations’ patents may be found at www.powerint.com.

The PI logo,

TOPSwitch

TinySwitch

and

EcoSmart

are registered trademarks of Power Integrations, Inc.

PI Expert

SINGAPORE

Power Integrations, Singapore

51 Goldhill Plaza #16-05

Republic of Singapore 308900

Phone: +65-6358-2160

Fax: +65-6358-2015

e-mail: singaporesales@powerint.com

WORLD HEADQUARTERS

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Main: +1 408-414-9200

Customer Service:

Phone: +1 408-414-9665

Fax: +1 408-414-9765

e-mail: usasales@powerint.com

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Power Integrations

International Holdings, Inc.

17F-3, No. 510

Chung Hsiao E. Rd.,

Sec. 5,

Taipei, Taiwan 110, R.O.C.

Phone: +886-2-2727-1221

Fax: +886-2-2727-1223

e-mail: taiwansales@powerint.com

CHINA

Power Integrations

International Holdings, Inc.

Rm# 1705, Bao Hua Bldg.

1016 Hua Qiang Bei Lu

Shenzhen Guangdong, 518031

China

Phone: +86-755-8367-5143

Fax: +86-755-8377-9610

e-mail: chinasales@powerint.com

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Power Integrations (Europe) Ltd.

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Easthampstead Road

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Phone: +44-1344-462-300

Fax: +44-1344-311-732

e-mail: eurosales@powerint.com

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Power Integrations

International Holdings, Inc.

8th Floor, DongSung Building,

17-8 Yoido-dong, Youngdeungpo-gu,

Seoul, 150-874, Korea

Phone: +82-2-782-2840

Fax: +82-2-782-4427

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