VIPER12A-E - STMicroelectronics

January 2006 DocRev1 1/21

VIPer12ADIP - E

VIPer12AS - E

Low Power OFF-Line SMPS Pr imary Switcher

Features

■Fixed 60kHZ S witching Frequ enc y

■9V to 38V Wide Range VDD Voltage

■Curren t Mode Control

■Auxiliary Undervoltage Lockout with Hysteresis

■High Voltage Start-up Current Source

■Overt emperature, Overcurrent and

Overv oltage Protection with Auto-Restart

■Typical power capabil ity

– Europe an (195 - 265 Vac) 8W for SO-8,

13W for DIP-8

– Europe an (85 - 265 Vac) 5W for SO-8,

8W for DIP- 8

Description

The VIPer12A combines a dedicated current

mode PW M controller with a high voltage Power

MOSFET on the same silicon chip.

Typical applications cover off line power supplies

for battery charger adapters, standby power

supp lies for TV or monitors, auxiliary supplies for

motor control, etc.

The internal control circuit offers the following

benefi ts:

– Large input voltage range on the VDD pin

accommodates changes in auxiliary supply

voltage. This feature is well adapted t o

battery charge r adapter configurations.

– Automatic burst mode in low load condition.

– Overvoltage protect i on in HICCUP mode.

DIP-8SO-8

www.st.com

Block diagram

ON/OFF

0.23 V

DRAIN

SOURCE

VDD

PWM

LATCH

60kHz

OSCILLATOR

BLANKING +

8/14.5V

R1 R4

REGULATOR

INTERNAL

SUPPLY

OVERVOLTAGE

LATCH

OVERTEMP.

DETECTOR

1 kΩ

42V _

SRQ

230 Ω

Contents VIPer12ADIP/ AS - E

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Contents

1 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.1 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Pin connections and function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4 Rectangular U-I Output characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5 Wide range of V DD voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

6 Feedback pin principle of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

7 Startup sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

8 Overvoltage threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

9 Operation pictures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

10 Mechanical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

11 Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

12 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

VIPe r12ADIP / AS - E Electri cal data

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1 Electrical data

1.1 Maximum rating

Stress ing the device above the rating listed in the “Absol ute Max imum Ratings” table may

cause permanent damage to the device. These ar e stress ratings only and operation of the

device at these or any o ther condi tions above those indicated in the Operat ing sections of

this specification is not implied. Exposure to Absolute Maximum Rating conditi ons for

extended periods may aff ect device reliability. Refer also t o the STMicroelectronics SURE

Program and other relevant quality documents.

Note: 1 This paramet er applies when the sta rt-up current source is OFF. This i s the case when the

VDD voltage has reached VDDon and remains above VDDoff.

2 This paramet er applies when the start up curren t source is on. T his is the case when the

VDD voltage has not yet re ac hed VDDon or has fallen below VDDoff.

1.2 Thermal data

Table 1. Absolute maxi mum rating

Symbol Parameter Value Unit

VDS(sw) Switching drain source volt age (TJ = 25 ... 125°C) Note 1 -0.3 ... 730 V

VDS(st) Start-up drain sou rce voltage (TJ = 25 ... 125°C) Note 2 -0.3 ... 400 V

ID Continuous drain current Internally limited A

VDD Supply vo ltage 0 ... 50 V

IFB Feedback current 3 mA

VESD Electrostatic dischar ge:

Machine m odel (R = 0 Ω; C = 200pF)

Charged device model 200

1.5 V

TJ Juncti on operating temper ature Inter nally limited °C

TC Case operating temperature -40 to 150 °C

Tstg Storage Temperature -55 to 150 °C

Table 2. Therm al data

Symbol Parameter SO-8 DIP-8 Unit

RthJC Thermal Resistance J unction-case Max 25 15 °C/W

RthJA Thermal Resistance Ambient-case (1)

1. When mounted on a standard single-sided FR4 board with 200 mm2 of Cu (at least 35 µm thick)

connec te d t o al l DRAIN pin s.

Max 55 45 °C/W

Electri cal character istics VIPer12ADIP/ AS - E

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2 Electrical characteristics

TJ = 25°C, VDD = 18V, unless otherwise specified

Note: 1 On clamped induct ive load

2 These test c onditions obtai ned with a resistive load are leading to the maximum conduction

time of the device.

Table 3. Pow er sectio n

Symbol Parameter Test conditions Min. Typ. Max. Unit

BVDSS Drain-source voltage ID = 1mA; VFB = 2V 730 V

IDSS O FF State drain

current VDS = 500V; VFB = 2V;

TJ = 125°C 0.1 mA

rDS(on) Static drain-source

ON sta te resist ance ID = 0.2A ID = 0.2A;

TJ = 100°C 27 30

54 Ω

tf Fall time ID = 0.1A; VIN = 300V

Note 1 (See Figure 8 on page 13) 100 ns

tr Rise time ID = 0.2A; VIN = 300V

Note 1 (See Figure 8 on page 13) 50 ns

COSS Drain capacitance VDS = 25V 40 pF

Table 4. Suppl y section

Symbol Parameter Test conditions Min. Typ. Max. Unit

IDDch Start-up chargi ng

current VDS = 100V; VDD = 5V ...VDDon

(See Figure 9 on page 13) -1 mA

IDDoff S tart- up charging

current in thermal

shutdown

VDD = 5V; VDS = 100V

TJ > TSD - THYST 0 mA

IDD0 Operating supply

current not switching IFB = 2mA 3 5 mA

IDD1 Operating supply

current switching IFB = 0.5mA; ID = 50mA

Note 2 4.5 mA

DRST Restart duty-cycle (See Figure 10 on page 13) 16 %

VDDoff VDD Undervoltage

shutdown threshold ( See Figure 9,

Figure 10 on p age 13) 7 8 9 V

VDDon VDD Start-up

threshold (See Figure 9,

Figure 10 on p age 13)) 13 14.5 16 V

VDDhyst VDD Threshold

hysteresis (See Figure 9 on page 13) 5.8 6.5 7.2 V

VDDovp VDD Overvoltage

threshold 38 42 46 V

VIPe r12ADIP / AS - E Electrical characteristics

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Table 5. Osc illation section

Symbol Parameter Test conditions Min. Typ. Max. Unit

FOSC Oscillator frequency

total var iat ion VDD = VDDoff ... 35 V;

TJ = 0 ... 10 0° C 54 60 66 kHz

Table 6. PWM Comparator section

Symbol Parameter Test Conditions Min. Typ. Max. Unit

GID I

FB to ID current gain ( See Figure 11 on page 14) 320

IDlim Peak cur rent

limitation VFB = 0V

(See Figure 11 on page 14) 0.32 0.4 0.48 A

IFBsd I

FB Shutdown curre nt (See Figure 11 on page 14) 0.9 mA

RFB FB Pin input

impedance ID = 0m A

(See Figure 11 on page 14) 1.2 kΩ

td Current sense del ay

to turn-OFF ID = 0.2A 200 ns

tb Blanking time 500 ns

tONmin Minimum Turn-ON

time 700 ns

Table 7. Ove rtemper ature section

Symbol Parameter Test Conditions Min. Typ. Max. Unit

TSD Th ermal shutdown

temperat ure (See Figure 12 on page 14) 140 170 °C

THYST Thermal shutdown

hysteresis (See Figure 12 on page 14) 40 °C

Table 8. Typ ic al Pow er Capability

Mains typ e SO-8 DIP-8

European (195 - 265 Vac) 8W 13W

US / Wide range (85 - 265 Vac) 5W 8W

Pin connections and function VIPer12ADIP/ AS - E

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3 Pin connections and function

Figure 1. Pin connection

Figure 2. Current and volta ge conven tions

Ta bl e 9. P in fu nct i on

Pin Name Pin Function

VDD

Power supply of the control circuits. Al so provides a char ging c u rr ent during st art up

thanks to a high voltage current source connected to the drain. For this purpose, an

hysteresis compara tor monitors the VDD voltage and provides t wo thresholds:

- VDDon: Voltage value (typically 14.5V) at which the device starts swit ching and turns

off the start up current source.

- VDDoff: Voltage v alue (typi cally 8V) at which th e device stops s w it ching and turns o n

the start up current source.

S OURCE Power MOSFET source and cir cuit ground refer ence.

DRAIN Power MOSFET dr ain. Also used by t he internal high voltage current source during

start up phase for charging the external V DD capa citor.

FB Feedback i npu t. The useful volt age range ex tend s from 0V to 1 V, and defi nes th e peak

drain MOSFET current. The current limitation, which corresponds to the maximum

drain current, is obtained for a FB pin shorted to t he SOURCE pin.

DRAIN

VDD

SOURCE

VDD

SOURCE

SOURCE SOURCE

SO-8 DIP-8

VDD DRAIN

SOURCE

CONTROL

VIPer12A

VIPe r12ADIP / AS - E Re ctangular U-I Output characteri stics

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4 Rect angular U-I Output character istics

Figure 3. Rect angular U-I output characteristics for battery charger

A complete regulation scheme can achieve combined and accurate output characteristics.

Figure 3. presents a secondary feedback through an optocoupler driven by a TSM101. This

device offe rs two operational amplifiers and a volt age r eference, thus allowing the regulation

of both o utpu t voltage and current. An i ntegr ated OR function perfo rms the combination of

the two resul ting error signals, leading to a d ual voltage and current limitati on, known as a

rect angular output characteristic. This type of power supply is especially useful for battery

chargers where the output is mainly u se d in current mode, in order to delive r a defined

charging rate. The accurate voltage re gulation is also convenient for Li-ion batteries which

require both modes of operation.

Wide range of VDD voltage VIPer12ADIP/ AS - E

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5 Wide range of VDD voltage

The VDD pin vol tage range extends from 9V to 38V. This feature offers a great flexibility in

design to achieve various behaviors. In Figure 3 on page 7 a forward configuration has been

chosen to supply the device with two benefits:

■As soon as the device starts switc hing, it immediately receives some energy from the

auxilia ry windi ng. C5 can be therefore reduc ed and a smal l ceramic c hip (100nF) is

sufficient to insure the filtering function. The total s tart up time from the switch on of i nput

voltage to output voltage presence is dramatically decreased .

■The output current characteristic can be maintained even with ve ry low or zero output

voltage. Since the TSM101 is also supplied i n forward mode, it keeps the current

regulation up whatever the output voltage is.The VDD pin voltage may vary as much as

the input voltage, that is to say with a ratio of about 4 for a wide range applica tion.

VIPe r12ADIP / AS - E Feedb ack pin principle of operation

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6 Feedback pin pri nciple of operation

A fe edbac k pin controls the operation of the device. Unlike convention al PWM contro l

circuits which use a voltage input (the inverted input of an operational amplifier), the FB pin

is sens itive to current. F igur e 4. presents the internal current mode s tructure.

Figure 4. Intern al cu rren t contro l struc ture

The Power MOSFET delivers a sense current Is which is proportional to the main c urrent Id.

R2 receives this current and the current coming fr om the FB pin. The volt age across R2 is

then compared to a fixed refe renc e voltage of about 0.23V. The MOSFET is switched off

when the following equation is reached:

By extracting IS:

Using the current sense rati o of the MOSFET GID:

R2ISIFB

+()⋅0.23V=

0.23V

----------------IFB

–=

IDGID IS

⋅GID 0.23V

----------------IFB

–

⎝⎠

⎛⎞

⋅==

Feedb ack pin principle of operation VIPer12ADI P/ AS - E

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The current limitation is obtained with the FB pin shorted to ground (VFB = 0V). Thi s leads t o

a negative current sourced by this pin, and expressed by:

By reporting this expression in th e previous one, it is possible to obtain the drain current

limitation I Dlim:

In a re al application, the FB pin is driven with an optocoup ler as shown on Figure 4. which

acts as a pull up. So, it is not possible to really short this pin to ground and the above drain

current value is not achievab le. Nevertheless, the capacitor C i s averaging the voltage on

the FB pin, and when the optocoupler is off (st art up or s hort circuit), it can be assumed that

the corresponding voltage is very clos e to 0V.

For low drain currents, the formula (1) is v alid as long as IFB satisfies IFB < IFBsd, where

IFBsd i s an internal threshold of the VIPer12A. If IFB exce eds this threshold the device will

stop switching. This is represented on Figure 1 1 o n pa ge 14, and IFBsd value is specified in the

PWM COMPAR ATOR SECTION. Actually, as soon as the drain curre nt is about 12% of

Idlim, that is to say 50 mA, the device will enter a burst mode operation by miss ing switching

cycles. This is espe cially important when the converter is lightly loaded.

Figure 5. IFB Transfer f unct io n

It is then possible to build the total DC transfer function between ID and IFB as shown on

Figure 5 on page 10. This figure also takes into account the internal blanking time and its

associated minimum turn on time. This imposes a minimum drain current unde r which the

device is no more able to control it in a linear way. This drain current depends on the primary

inductance value of the transformer and the input volt age. T wo cases may occur , depending

on the value of this curre nt versus the fixed 50mA value, as described above.

IFB 0.23V

----------------–=

IDlim GID 0.23V 1

-------1

-------+

⎝⎠

⎛⎞

⋅⋅=

VIPer12ADIP/ AS - E Startup sequence

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7 Startup sequence

Figure 6. Startup sequence

This device includes a high voltag e start up current source connect ed on the drain of the

device. As soon as a vol tage is applied on the input of the converter, this start up current

source is activated as long as VDD is lower than VDDon. When reaching VDDon, the start up

current source is switched off and the device begins to operate by turning on and off it s main

power MOSFET. As t he FB pin does not receive any current from the optocoupler, the

device operates at full current capacity and the output voltage rises until reaching the

regulation point where the secondary loop begins to send a current in the optocoupler. At

this point, the converter enters a regulated operation where the FB pin receiv es the amount

of current needed to delive r the right power on secondary side.

This sequence is shown in Figure 6. Note that during the real starting phase tss, the device

consumes some energy from the VDD capacitor, waiting for the auxiliary winding to provide

a continuous supply. If the v alue of this capacitor is too low, the start up phase is terminated

before receiving any energy from the auxiliary winding an d the converte r never starts up.

This is illustrated also in the same figure in dashed lines.

Overvo ltag e thresh old VIPer12ADIP/ AS - E

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8 Overvoltage threshold

An overvoltage detector on the VDD pin al lows the VIPer12A to reset itself when VDD

ex ce eds VDDovp. This is ill u s tra t ed in Figure 7., which shows the whole sequence of an

overvoltage event. Note that this ev ent is only latched for the time needed by VDD to reach

VDDoff, and then the device resumes normal opera tion automaticall y.

Figure 7. Overvoltage Sequence

VDS

VDDon

VDD

VDDoff

VDDovp

VI Pe r1 2A D I P / AS - E O peratio n pi c ture s

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9 Operation pictures

Figure 8. Rise and Fall time

Figure 9. Start-up VDD current

Figure 10. Restart duty-cycle

Opera tion pictures VIPer12ADIP/ AS - E

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Figure 1 1. Peak drain current Vs. feedback current

Figure 12. T hermal shutdown

VI Pe r1 2A D I P / AS - E O peratio n pi c ture s

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Figure 13. Switching frequency Vs. temperature

Figure 14. Current Limitation vs. Temperature

Mechanical Data VIPer12ADIP/ AS - E

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10 Mechanical Data

In order to meet environ men tal requirements, ST offers these dev ices in ECOPACK ®

packages. These packages have a Lead-fr ee second level interconnect. The category of

second Level Interconnect is marked on the package and on the inner box label, in

compliance with JEDEC Standard JESD97. The maximum ratings related to soldering

conditions are also marked on the inner box label. ECOPA CK is an ST trademark.

ECOPA CK spec ifications are available at: www.st.com.

VIPer12ADI P / AS - E Mech anical Data

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Figure 15. Package Dimensions

Table 10. DIP8 Mechanical Data

Dimensions

Ref. Databook (mm)

Nom. Min Max

A5.33

A1 0.38

A2 2.92 3.30 4.95

b 0.36 0.46 0.56

b2 1.14 1.52 1.78

c 0.20 0.25 0.36

D 9.02 9.27 10.16

E 7.62 7.87 8.26

E1 6.10 6.35 7.11

e2.54

eA 7.62

eB 10.92

L 2.92 3.30 3.81

Package W eight Gr. 470

Mechanical Data VIPer12ADIP/ AS - E

18/21 DocRev1

Figure 16. Package Dimensions

Table 11. S O8 M echan ic al Data

Dimensions

Ref. Databook (mm)

Nom. Min Max

A 1.35 1.75

A1 0.10 0.25

A2 1.10 1.65

B 0.33 0.51

C 0.19 0.25

D 4.80 5.00

E 3.80 4.00

e 1.27

H 5.80 6.20

h 0.25 0.50

L 0.40 1.27

k 8° (max.)

ddd 0.1

VIPer12ADIP/ AS - E Order codes

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11 Order codes

Table 12. Order co des

Part Number Package Shipment

VIPER12ASTR-E SO-8 Tape and Reel

VIPer12AS - E SO-8 Tube

VIPer12ADIP - E DIP-8 Tube

Revision history VIPer12ADIP/ AS - E

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12 Revision history

Table 13. Document revision history

Date Revision Changes

09-Jan-2006 1Initial re le a s e.

VIPer12ADI P / AS - E Revi sion history

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