ML7924A - Micro Electronics Corporation

■ Package Outline TO-220 TO-220F

(7900A) (7900FA)

ABSOLUTE MAXIMUM RATINGS (Ta=25℃)

PARAMETER SYMBOL UNIT

Storage Temperature Range Tstg ℃

Topr

Power Dissipation PDW

THERMAL RESISTANCE

Θ ja

Θ jc

PARAMETER SYMBOL MIN. TYP. MAX. UNIT

ML7905A / ML7905FA

Output Voltage Vo VIN=-10V Io=0.5A -4.8 -5.0 -5.2 V

Quiescent Current IQVIN=-10V Io=0mA - 2.2 5.0 mA

Load Regulation ΔVo Io VIN=-10V - 50 100 mV

Line Regulation ΔVo Vin VIN=-7 to -25V Io=0.5A - 12.5 100 mV

Ripple Rejection RR VIN=-10V Io=0.5A ein=2Vp-p f=120Hz 54 60 -dB

Output Noise Voltage VNO VIN=-10V Io=0.5A - 125 -μV

Average Temperature

Cofficient of Out

ut Volta

ΔVo / ΔTVIN=-10V Io=5mA - -0.4 - mV/℃

APR 2005

TEST CONDITIONS

BW=10Hz to 100KHz

Io=0.005A to 1.5A

Maximum Rating

ML7905 to ML7909

ML7912 to ML7920

ML7924

Operating Junction Temperature

15(Tc≦45℃ )

VIN

℃

-30 to +125

-30 to +75

Input Voltage

-40 to +125

-35

-40

Junction-to-Case

Operating Temperature

Range Operating Ambient Temperature

The ML7900 series are 3-Terminal Negative Voltage Regulators. These negative regulators are intended as complements to

the popular ML7800 series of positive voltage regulations, and they are available in the same voltage options from -5V to -

24V. The ML7900 series employ internal current-limiting. safe-area protection , and thermal shutdown, making them

virtually indestructible.

* Parts of FBE are satisfied with requirements of directive 2002/95/EC on RoHS.

3-TERMINAL NEGATIVE

VOLTAGE REGULATOR

℃/W

(Tj=25℃,C1=0.33μF,Co=0.1μF)

ELECTRICAL CHARACTERISTICS Measurement is to be conducted

in pulse testing.

Thermal Resistance Junction-to-Ambient Temperature

1. OUT

2. IN

3. COMMON

ML7900 - FBE*

SERIES

321

MICRO ELECTRONICS LTD.

7/F, Enterprise Square Three, 39 Wang Chiu Road, Kowloon Bay, Kowloon, Hong Kong.

Fax: (852) 2341 0321 Tel: (852) 2343 0181-5 Website: www.microelectr.com.hk

Page 1 of 10

PARAMETER SYMBOL MIN. TYP. MAX. UNIT

ML7906A / ML7906FA

Output Voltage Vo VIN=-11V Io=0.5A -5.75 -6.0 -6.25 V

Quiescent Current IQVIN=-11V Io=0mA - 2.2 5.0 mA

Load Regulation ΔVo Io VIN=-11V - 50 120 mV

Line Regulation ΔVo Vin VIN=-8 to -25V Io=0.5A - 12.5 120 mV

Ripple Rejection RR VIN=-11V Io=0.5A ein=2Vp-p f=120Hz 54 60 -dB

Output Noise Voltage VNO VIN=-11V Io=0.5A - 150 -μV

Average Temperature

Cofficient of Out

ut Volta

ΔVo / ΔTVIN=-11V Io=5mA - -0.4 - mV/℃

ML7908A / ML7908FA

Output Voltage Vo VIN=-14V Io=0.5A -7.7 -8.0 -8.3 V

Quiescent Current IQVIN=-14V Io=0mA - 2.2 5.0 mA

Load Regulation ΔVo Io VIN=-14V - 60 160 mV

Line Regulation ΔVo Vin VIN=-10.5 to -25V Io=0.5A - 12.5 160 mV

Ripple Rejection RR VIN=-14V Io=0.5A ein=2Vp-p f=120Hz 54 60 -dB

Output Noise Voltage VNO VIN=-14V Io=0.5A - 200 -μV

Average Temperature

Cofficient of Out

ut Volta

ΔVo / ΔTVIN=-14V Io=5mA - -0.7 - mV/℃

ML7909A / ML7909FA

Output Voltage Vo VIN=-15V Io=0.5A -8.65 -9.0 -9.35 V

Quiescent Current IQVIN=-15V Io=0mA - 2.2 5.0 mA

Load Regulation ΔVo Io VIN=-15V - 60 180 mV

Line Regulation ΔVo Vin VIN=-11.5 to -25V Io=0.5A - 8 180 mV

Ripple Rejection RR VIN=-15V Io=0.5A ein=2Vp-p f=120Hz 54 60 -dB

Output Noise Voltage VNO VIN=-15V Io=0.5A - 250 -μV

Average Temperature

Cofficient of Out

ut Volta

ΔVo / ΔTVIN=-15V Io=5mA - -0.8 - mV/℃

ML7912A / ML7912FA

Output Voltage Vo VIN=-19V Io=0.5A -11.5 -12.0 -12.5 V

Quiescent Current IQVIN=-19V Io=0mA - 2.7 6.0 mA

Load Regulation ΔVo Io VIN=-19V - 60 240 mV

Line Regulation ΔVo Vin VIN=-14.5 to -30V Io=0.5A - 5 240 mV

Ripple Rejection RR VIN=-19V Io=0.5A ein=2Vp-p f=120Hz 54 60 -dB

Output Noise Voltage VNO VIN=-19V Io=0.5A - 300 -μV

Average Temperature

Cofficient of Out

ut Volta

ΔVo / ΔTVIN=-19V Io=5mA - -0.8 - mV/℃

ELECTRICAL CHARACTERISTICS (Tj=25℃,C1=0.33μF,Co=0.1μF) Measurement is to be conducted

in pulse testing.

TEST CONDITIONS

Io=0.005A to 1.5A

BW=10Hz to 100KHz

Io=0.005A to 1.5A

BW=10Hz to 100KHz

Io=0.005A to 1.5A

BW=10Hz to 100KHz

Io=0.005A to 1.5A

BW=10Hz to 100KHz

Page 2 of 10

PARAMETER SYMBOL MIN. TYP. MAX. UNIT

ML7915A / ML7915FA

Output Voltage Vo VIN=-23V Io=0.5A -14.4 -15.0 -15.6 V

Quiescent Current IQVIN=-23V Io=0mA - 2.7 6.0 mA

Load Regulation ΔVo Io VIN=-23V - 60 300 mV

Line Regulation ΔVo Vin VIN=-17.5 to -30V Io=0.5A - 5 300 mV

Ripple Rejection RR VIN=-23V Io=0.5A ein=2Vp-p f=120Hz 54 60 -dB

Output Noise Voltage VNO VIN=-23V Io=0.5A - 375 -μV

Average Temperature

Cofficient of Out

ut Volta

ΔVo / ΔTVIN=-23V Io=5mA - -1 - mV/℃

ML7918A / ML7918FA

Output Voltage Vo VIN=-27V Io=0.5A -17.3 -18.0 -18.7 V

Quiescent Current IQVIN=-27V Io=0mA - 2.7 6.0 mA

Load Regulation ΔVo Io VIN=-27V - 60 360 mV

Line Regulation ΔVo Vin VIN=-21 to -33V Io=0.5A - 5 360 mV

Ripple Rejection RR VIN=-27V Io=0.5A ein=2Vp-p f=120Hz 54 60 -dB

Output Noise Voltage VNO VIN=-27V Io=0.5A - 450 -μV

Average Temperature

Cofficient of Out

ut Volta

ΔVo / ΔTVIN=-27V Io=5mA - -1 - mV/℃

ML7924A / ML7924FA

Output Voltage Vo VIN=-33V Io=0.5A -23.0 -24.0 -25.0 V

Quiescent Current IQVIN=-33V Io=0mA - 2.7 6.0 mA

Load Regulation ΔVo Io VIN=-33V - 85 480 mV

Line Regulation ΔVo Vin VIN=-28 to -38V Io=0.5A - 5 480 mV

Ripple Rejection RR VIN=-33V Io=0.5A ein=2Vp-p f=120Hz 54 60 -dB

Output Noise Voltage VNO VIN=-33V Io=0.5A - 600 -μV

Average Temperature

Cofficient of Out

ut Volta

ΔVo / ΔTVIN=-33V Io=5mA - -1 - mV/℃

ELECTRICAL CHARACTERISTICS (Tj=25℃,C1=0.33μF,Co=0.1μF) Measurement is to be conducted

in pulse testing.

TEST CONDITIONS

Io=0.005A to 1.5A

BW=10Hz to 100KHz

Io=0.005A to 1.5A

BW=10Hz to 100KHz

Io=0.005A to 1.5A

BW=10Hz to 100KHz

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■Equivalent Circuit

■Power Dissipation vs. Ambient Temperature

■Test Circuit

1. 2.Output Voltage, Line Regulation, Load

Regulation, Quiescent Current,

Average Temperature Coefficient of

Output Voltage, Output Noise Voltage.

Ripple Rejection

25 50 75

Power Dissipation P

(W)

Ambient Temperature Ta ( C)

Wi th out Heat S ink

HS = 20 C/W

HS = 10 C/W

HS = 5 C/W

HS = 3 C/W

Heat Sink

HS = Heat S i nk T hermal R esistan ce

2 1

Page 4 of 10

■Typical Characteristics

Page 5 of 10

■Typical Characteristics

Page 6 of 10

1. Application Circuit

Positive/Negative Voltage Supply

Note :

2. Note in Application Circuit

( 1 )

( 2 )

* In case of negative voltage regulator, reverse the SBD and capacitor direction.

In the following explain only the positive regulator unless otherwise specified. However they can apply to the

negative voltage regulator by easy change.

In the above positive and negative

power supply application, D1 and D2

should be connected. If D1 and D2

are not connected, either of positive

or negative power supply circuit may

not turns on.

If the higher voltage (above the rated value) or lower voltage (GND-0.5V) is supplied to the input

terminals, the IC may be destroyed. To avoid such a case, a zener diode or other parts of the surge

supressor should be connected as shown below.

If the higher voltage than the input terminal is supplied to the output terminal, the IC may be

destroyed. To avoid input terminal short to the GND or the stored voltage in the capacitor back to the

output terminal, by the large value capacitor connecting to the output terminal application, the SBD

should be required as shown below;

COM

-Vin

+Vin

0.33uF

OUT

COM

79 series

OUT

GND

78 series

-Vo

+Vo

0.1uF

Vin Vo

GND 2

OUT 3

Capacitor

Zener Di ode

VoVin

Capacitor

GND 2

OUT 3

Diode

Vin Vo

Capacitor

GND 2

OUT 3

DIODE

Page 7 of 10

3. Thermal Design

( 1 ) Heat Producting

(1-1) PLOSS-1 : heat producting by own operation

PLOSS-1 = Vin X IQ

(1-2) PLOSS-2 : heat producing by output current and the input-output differential voltage.

Internal power transistor produces the hest mentioned following equation.

PLOSS-2 = (Vin-Vout) x Iout (W)

Therefore, the total heat producing PLOSS is :

PLOSS = PLOSS-1 + PLOSS-2

= Vin X IQ + (Vin-Vout) X Iout (W)

( 2 ) Thermal Resistance

(2-1) Definition of Thermal Resistance : θ

Thermal resistance (θ ) is a degree of heat radiation mentioned following equation.

= (T1 - T2)/P (℃ /W) Heat Producing Quantity : P (W)

Ambient Temperature or case temperature :T2 (℃ )

Heat Source Temperature :T1 (℃ )

(2-2) Thermal resistance of TO-220

θjc :

θja : thermal resistance between IC chip (junction point) and ambience.

Input voltage (Vin) and quiescent current (IQ) produce the heat mentioned below equation.

There are two kinds of heat producting (PLOSS-1, PLOSS-2) in three terminal regulator and the sum of

them is total heat producting of IC (PLOSS).

There are two kinds of thermal resistance of TO-220. One is "θjc" for the application with the heat

sink, the other is "θja" for the application without the heat sink.

thermal resistance between IC chip (junction point) and the package back side

contacting with the heat sink.

Input

GND

IN OUT Output

Vin Vout

Iout

T1 T2

P(W)

T1 > T2

Page 8 of 10

( 3 ) Heat Radiation Balance

(3-1) TO-220 with heat sink

Where θjc :

θjs :

θCH :

θHS :

The relation between temperature and heat radiation quantity is shown below.

Tj=PLOSS X (θjc+θCH +θHS) + Ta (℃ )

The heat produced in the IC is radiated to ambience through the package and the heat

sink.

The quantity of the heat radiation depends on the heat source temperature, ambient

temperature and the thermal resistance of the package.

Heat radiation balance model of the TO-220 with heat sink is shown as below.

thermal resistance between IC chip (junction point) and the

package backside connecting to the heatsink.

thermal resistance between IC chip (junction point) and the

package surface.

thermal resistance between package backside and the heat sink

including the condidtion of insulator, silicon grease and

tighten torque.

thermal resistance of the heat sink

If the js is large enough compare with other thermal resistance, the js can be neglected and the

heat radiation model can be mentioned as below.

Tj Ta

LOSSP

Ambient

Temperature

Heat Source

(junction)

Temperature

JCθθCH θHS

θJS

Heat Sink

Package

Face Side

Resin

Chip

Package

Back Side

θJS

θJC

θCH

θHS

LOSSPθJC θCH

θHS

Page 9 of 10

( 4 ) Thermal Design

The heat radiation balance model of the TO-220 with the heat sink is shown as follows.

Heat radiation balance

Tj = PLOSS X (θjc +θCH + θHS) + Ta (℃ ) (4-1)

PLOSS = Vin X IQ + (Vin-Vout) X Iout (W) (4-2)

Substituting "Eq.(4-2) into "Eq.(4-1)" obtains

Tj = [Vin X IQ +(Vin-Vout) X Iout] X (θjc +θCH +θHS)+Ta (℃) (4-3)

In Eq.(4-3)

Vin, Iout, θCH, θHS, Ta depand on using condition.

Tj, IQ,Vout,θjc depend on IC depend on IC specification.

WhenθCH, IQ and Tj are assumed the following values,

Eq.(4-3) becomes Eq.(4-4).

θCH=0.3 to 0.4 (℃/W)

IQ = 5 to 6mA (max.)

Tj = 125℃ (max.)

Tj(max) = 125 = [5 X Vin + (Vin-Vout) X Iout] X (5+0.3+θHS) +Ta (℃) (4-4)

When fix the Vout, Tj depends on the Vin, Iout, θHS and Ta.

It means;

For more detail, please refer the heat resistance value mentioned in the specification of the heat sink

supplier.

Insert the mica paper (0.1t) and thermal conduction silicon grease between

the IC and heat sink and tighten them with the bolt by 4Kg*cm-min.

Lower Vin and / or Iout are required to linit the temperature rise.

Smaller θHS is required for the effective heat reduce (i.e. using the large heat sink).

In the thermal design, when fix the Vin, Iout and Ta, selectthe heat sink which θHS is smaller that

the result of Eq.(4-4).

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