Datasheet MC7924, MC7912, MC7912A, MC7910, MC7918 Datasheet (Fairchild Semiconductor)

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MC79XX/MC79XXA/LM79XX

3-Terminal 1A Negative Voltage Regulator

Features

• Output Current in Excess of 1A

• Output Voltages of -5, -6, -8 , -9, -10, -12, -15, -18 and ­24V

• Internal Thermal Overload Protection

• Short Circuit Protection

• Output Transistor Safe Operating Area Compensation

Internal Block Digram

Description

The MC79XX / MC79XXA/ LM79XX series of three
terminal negative regulators are available in TO-220
package and with several fixed output voltages, making
them useful in a wide range of applications. Each type
employs internal current limiting, thermal shut down and
safe operating area protection, making it essentially
indestructible.

TO-220

1

1. GND 2. Input 3. Output

Vin

GND

VOLTAGE

REFERENCE

I1 I2

©2002 Fairchild Semiconductor Corporation

R1

R2

Output

Q2

Rsc

Out

In

Input

+

Q1

-

PROTECTION

CIRCUITRY

Rev. 1.0.1

MC79XX/MC79XXA/LM79XX

Absolute Maximum Ratings

Parameter Symbol Value Unit

Input Voltage V
Thermal Resistance Junction-Case (Note1) R
Thermal Resistance Junction-Air (Note1, 2) R
Operating Temperature Range T
Storage Temperature Range T

Note:

1. Thermal resistance test board

Size: 76.2mm * 114.3mm * 1.6mm(1S0P)
JEDEC standard: JESD51 -3, JESD51-7

2. Assume no ambient airflow

I

θJC
θJA

OPR
STG

-35 V
5

65

°C/W

0 ~ +125 °C

-65 ~ +150 °C

Electrical Characteristics (MC7905/LM7905)

(V

= -10V, IO = 500mA, 0°C ≤T

I

Parameter Symbol Conditions Min. Typ. Max. Unit

Output Voltage V

Line Regulation (Note3) ∆V

Load Regulation (Note3) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of V

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

≤ +125°C, C

J

∆Vo/∆TI

D

Q

SC
PK

=2.2µF, CO =1µF, unless otherwise specified.)

I

TJ = +25°C -4.8 -5.0 -5.2

O

O

O

= 5mA to 1A, P

I

O

V

= -7V to -20V

I

TJ = +25°C
TJ = +25°C

I

= 5mA to 1.5A

O

=+25°C

T

J

I

= 250mA to 750mA

O

15W

O ≤

V

= -7V to -25V - 35 100

I

= -8V to -12V - 8 50

V

I

-4.75 -5.0 -5.25

- 10 100

-350

TJ =+25°C-36mA
IO = 5mA to 1A - 0.05 0.5

Q

N

D

= -8V to -25V - 0.1 0.8

V

I

= 5mA - - 0.4 - mV/°C

O

f = 10Hz to 100kHz
T

=+25°C

A

f = 120Hz

= 10V

∆V

I

TJ = +25°C
I

= 1A

O

-40- µV

54 60 - dB

-2- V

TJ =+25°C, VI = -35V - 300 - mA
TJ =+25°C-2.2-A

V

mV

mV

mA

Note

3. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

2

due to heating e ffe cts mus t be t ak en

O

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7906)

(V

= -11V, IO = 500mA, 0°C ≤T

I

≤ +125°C, C

J

I

(Continued)

=2.2µF, CO =1µF, unless otherwise specified.)

Parameter Symbol Conditions Min. Typ. Max. Unit

TJ = +25°C -5.75 -6 -6.25

Output Voltage V

Line Regulation (Note1) ∆V

Load Regulation (Note1) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of V

D

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

O

I

O

V

I

TJ = +25°C

O

TJ = +25°C
I

O

O

T

J

I

O

TJ =+25°C-36mA

Q

IO = 5mA to 1A - 0.05 0.5

Q

V

I

∆Vo/∆TI

N

O

f = 10Hz to 100kHz
T

A

f = 120Hz
∆V

TJ = +25°C

D

I

O
SC
PK

TJ = +25°C, VI = -35V - 300 - mA
TJ = +25°C-2.2-A

= 5mA to 1A, P
= -9V to -21V

= 5mA to 1.5A

=+25°C

= 250mA to 750mA

≤ 15W

O

V

= -8V to -25V - 10 120

I

= -9V to -13V - 5 60

V

I

-5.7 -6 -6.3

- 10 120

-360

= -8V to -25V - 0.1 1.3
= 5mA - -0.5 - mV/°C

=+25°C

= 10V

I

= 1A

- 130 - µV

54 60 - dB

-2- V

V

mV

mV

mA

Note

1. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

due to heating eff e cts mus t be t aken

O

3

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7908)

(V

= -14V, IO = 500mA, 0°C ≤T

I

≤ +125°C, C

J

I

(Continued)

=2.2µF, CO =1µF, unless otherwise specified.)

Parameter Symbol Conditions Min. Typ. Max. Unit

TJ = +25°C -7.7 -8 -8.3

Output Voltage V

Line Regulation (Note1) ∆V

Load Regulation (Note1) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of V

D

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

O

I

O

V

I

TJ = +25°C

O

TJ = +25°C
I

O

O

T

J

I

O

TJ =+25°C-36mA

Q

IO = 5mA to 1A - 0.05 0.5

Q

V

I

∆Vo/∆TI

O

f = 10Hz to 100kHz

N

T

A

f = 120Hz
∆V

TJ = +25°C

D

I

O

SC

PK

TJ = +25°C, VI = -35V - 300 - mA
TJ = +25°C-2.2-A

= 5mA to 1A, P
= -10V to -23V

= 5mA to 1.5A

=+25°C

= 250mA to 750mA

≤ 15W

O

V

= -10.5V to -25V - 10 160

I

= -11V to -17V - 5 80

V

I

-7.6 -8 -8.4

- 12 160

-480

= -10.5V to -25V - 0.1 1
= 5mA - -0.6 - mV/°C

=+25°C

= 10V

I

= 1A

- 175 - µV

54 60 - dB

-2- V

V

mV

mV

mA

Note

1. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

due to heating e ffe cts mus t be t ak en

O

4

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7909)

(V

= -15V, IO = 500mA, 0°C ≤T

I

≤ +125°C, C

J

I

(Continued)

=2.2µF, CO =1µF, unless otherwise specified.)

Parameter Symbol Conditions Min. Typ. Max. Unit

TJ = +25°C -8.7 -9.0 -9.3

Output Voltage V

Line Regulation (Note1) ∆V

Load Regulation (Note1) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of V

D

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

O

I

O

V

I

TJ = +25°C

O

TJ = +25°C
I

O

O

T

J

I

O

TJ = +25°C-36mA

Q

IO = 5mA to 1A - 0.05 0.5

Q

V

I

∆Vo/∆TI

N

O

f = 10Hz to 100kHz
T

A

f = 120Hz
∆V

TJ = +25°C

D

I

O
SC
PK

TJ = +25°C, VI = -35V - 300 - mA
TJ = +25°C-2.2-A

= 5mA to 1A, P

= -1.5V to -23V

= 5mA to 1.5A

= +25°C

= 250mA to 750mA

≤ 15W

O

V

= -11.5V to -26V - 10 180

I

= -12V to -18V - 5 90

V

I

-8.6 -9.0 -9.4

- 12 180

-490

= -11.5V to -26V - 0.1 1

= 5mA - -0.6 - mV/°C

= +25°C

= 10V

I

= 1A

- 175 - µV

54 60 - dB

-2-V

V

mV

mV

mA

Note:

1. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

due to heating eff e cts mus t be t aken

O

5

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7910)

(V

= -17V, IO = 500mA, 0°C ≤T

I

≤ +125°C, C

J

I

(Continued)

=2.2µF, CO =1µF, unless otherwise specified.)

Parameter Symbol Conditions Min. Typ. Max. Unit

TJ = +25°C -9.6 -10 -10.4

Output Voltage V

Line Regulation (Note1) ∆V

Load Regulation (Note1) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of V

O

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

O

I

O

V

I

TJ = +25°C

O

TJ = +25°C
I

O

O

T

J

I

O

Q

TJ = +25°C-36mA
IO = 5mA to 1A - 0.05 0.5

Q

V

I

∆Vo/∆TI

N

O

10Hz ≤ f ≤ 100kHz
T

A

f = 120Hz
∆V

TJ = +25°C

D

I

O
SC
PK

TJ = +25°C, VI = -35V - 300 - mA
TJ = +25°C-2.2-A

= 5mA to 1A, P

= -12V to -28

= 5mA to 1.5A

= +25°C

= 250mA to 750mA

≤ 15W

d

V

= -12.5V to -28V - 12 200

I

= -14V to -20V - 6 100

V

I

-9.5 -10 -10.5

- 12 200

- 4 100

= -12.5V to -28V - 0.1 1

= 5mA - -1 - mV/°C

=+25°C

= 10V

I

= 1A

- 280 - µV

54 60 - dB

-2-V

V

mV

mV

mA

Note:

1. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

due to heating eff e cts mus t be t aken

O

6

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7912)

(V

= -19V, IO = 500mA, 0°C ≤T

I

≤ +125°C, C

J

I

(Continued)

=2.2µF, CO =1µF, unless otherwise specified.)

Parameter Symbol Conditions Min. Typ. Max. Unit

TJ = +25°C -11.5 -12 -12.5

Output Voltage V

Line Regulation (Note1) ∆V

Load Regulation (Note1) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of V

D

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

O

I

O

V

I

TJ = +25°C

O

TJ = +25°C
I

O

O

T

J

I

O

TJ = +25°C-36mA

Q

IO = 5mA to 1A - 0.05 0.5

Q

V

I

∆Vo/∆TI

N

O

f = 10Hz to 100kHz
T

A

f = 120Hz
∆V

TJ = +25°C

D

I

O
SC
PK

TJ = +25°C, VI = -35V - 300 - mA
TJ = +25°C-2.2-A

= 5mA to 1A, P

= -15.5V to -27V

= 5mA to 1.5A
= +25°C

= 250mA to 750mA

≤ 15W

O

V

= -14.5V to -30V - 12 240

I

= -16V to -22V - 6 120

V

I

-11.4 -12 -12.6

- 12 240

- 4 120

= -14.5V to -30V - 0.1 1

= 5mA - -0.8 - mV/°C

= +25°C

= 10V

I

= 1A

- 200 - µV

54 60 - dB

-2- V

V

mV

mV

mA

Note:

1. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

due to heating e ffe cts mus t be t ak en

O

7

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7915)

(V

= -23V, IO = 500mA, 0°C ≤T

I

≤ +125°C, C

J

I

(Continued)

=2.2µF, CO =1µF, unless otherwise specified.)

Parameter Symbol Conditions Min. Typ. Max. Unit

TJ = +25°C -14.4 -15 -15.6

Output Voltage V

Line Regulation (Note1) ∆V

Load Regulation (Note1) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of V

D

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

O

I

O

V

I

TJ = +25°C

O

TJ = +25°C
I

O

O

T

J

I

O

Q

TJ = +25°C-36mA
IO = 5mA to 1A - 0.05 0.5

Q

V

I

∆Vo/∆TI

N

O

f = 10Hz to 100kHz
T

A

f = 120Hz
∆V

TJ = +25°C

D

I

O
SC
PK

TJ = +25°C, VI = -35V - 300 - mA
TJ = +25°C-2.2-A

= 5mA to 1A, P

= -18V to -30V

= 5mA to 1.5A

= +25°C

= 250mA to 750mA

≤ 15W

O

V

= -17.5V to -30V - 12 300

I

= -20V to -26V - 6 150

V

I

-14.25 -15 -15.75

- 12 300

- 4 150

= -17.5V to -30V - 0.1 1

= 5mA - -0.9 - mV/°C

=+25°C

= 10V

I

= 1A

- 250 - µV

54 60 - dB

-2-V

V

mV

mV

mA

Note:

1. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

due to heating eff e cts mus t be t aken

O

8

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7918)

(V

= -27V, IO = 500mA, 0°C ≤T

I

≤ +125°C, C

J

I

(Continued)

=2.2µF, CO =1µF, unless otherwise specified.)

Parameter Symbol Conditions Min. Typ. Max. Unit

TJ = +25°C -17.3 -18 -18.7

Output Voltage V

Line Regulation (Note1) ∆V

Load Regulation (Note1) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of V

D

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

O

I

O

V

I

TJ = +25°C

O

TJ = +25°C
I

O

O

T

J

I

O

TJ = +25°C-36mA

Q

IO = 5mA to 1A - 0.05 0.5

Q

V

I

∆Vo/∆TI

O

f = 10Hz to 100kHz

N

T

A

f = 120Hz
∆V

TJ = +25°C

D

I

O

SC

PK

TJ = +25°C, VI = -35V - 300 - mA
TJ = +25°C-2.2-A

= 5mA to 1A, P
= -22.5V to -33V

= 5mA to 1.5A

= +25°C

= 250mA to 750mA

≤ 15W

O

V

= -21V to -33V - 15 360

I

= -24V to -30V - 8 180

V

I

-17.1 -18 -18.9

- 15 360

- 5 180

= -21V to -33V - 0.1 1
= 5mA - -1 - mV/°C

= +25°C

= 10V

I

= 1A

- 300 - µV

54 60 - dB

-2- V

V

mV

mV

mA

Note:

1. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

due to heating e ffe cts mus t be t ak en

O

9

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7924)

(V

= -33V, IO = 500mA, 0°C ≤T

I

≤ +125°C, C

J

I

(Continued)

=2.2µF, CO =1µF, unless otherwise specified.)

Parameter Symbol Conditions Min. Typ. Max. Unit

TJ = +25°C -23 -24 -25

Output Voltage V

Line Regulation (Note1) ∆V

Load Regulation (Note1) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of V

D

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

O

I

O

V

I

TJ = +25°C

O

TJ = +25°C
I

O

O

T

J

I

O

Q

TJ = +25°C-36mA
IO = 5mA to 1A - 0.05 0.5

Q

V

I

∆Vo/∆TI

N

O

f = 10Hz to 100kHz
T

A

f = 120Hz
∆V

TJ = +25°C

D

I

O
SC
PK

TJ = +25°C, VI = -35V - 300 - mA
TJ = +25°C-2.2-A

= 5mA to 1A, P

= -27V to -38V

= 5mA to 1.5A

= +25°C

= 250mA to 750mA

≤ 15W

O

V

= -27V to -38V - 15 480

I

= -30V to -36V - 8 180

V

I

-22.8 -24 -25.2

- 15 480

- 5 240

= -27V to -38V - 0.1 1

= 5mA - -1 - mV/°C

= +25°C

= 10V

I

= 1A

- 400 - µV

54 60 - dB

-2- V

V

mV

mV

mA

Note:

1. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

due to heating effects must be taken

O

10

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7905A)

(V

= -10V, IO = 500mA, 0°C ≤T

I

≤ +125°C, C

J

=2.2µF, CO =1µF, unless otherwise specified.)

I

(Continued)

Parameter Symbol Conditions Min. Typ. Max. Unit

TJ = +25°C -4.9 -5.0 -5.1

Output Voltage V

Line Regulation (Note1) ∆V

O

O

= 5mA to 1A, P

I

O

= -7V to -20V

V

I

TJ = +25°C

= -7.5V to -25V - 7 50

V

I

= -8V to -12V , IO=1A - 7 50

V

I

≤ 15W

O

V

= -7V to -20V IO=1A - 5 50

I

= -8V to -12V IO=1A - 2 25

V

I

- 4.8 -5.0 -5.2

TJ =+25°C, IO = 5mA to 1.5A - 10 100

Load Regulation (Note1) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of

V

D

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

O

T
I

O

TJ = +25°C-36mA

Q

IO = 5mA to 1A - 0.05 0.5

Q

V

∆Vo/∆TI

O

f = 10Hz to 100kHz

N

T
f = 120Hz

∆V
TJ = +25°C

D

I

O

SC

TJ = +25°C, VI = -35V - 300 - mA
TJ = +25°C-2.2-A

PK

= +25°C

J

= 250mA to 750mA

= -8V to -25V - 0.1 0.8

I

-350

= 5mA - - 0.4 - mV/°C

= +25°C

A

= 10V

I

= 1A

-40- µV

54 60 - dB

-2- V

V

mV

mV

mA

Note:

1. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

due to heating eff e cts mus t be t aken

O

11

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7912A)

(V

= -19V, IO = 500mA, 0°C ≤T

I

≤ +125°C, C

J

=2.2µF, CO =1µF, unless otherwise specified.)

I

(Continued)

Parameter Symbol Conditions Min. Typ. Max. Unit

TJ = +25°C -11.75 -12 -12.25

Output Voltage V

Line Regulation (Note1)

Load Regulation (Note1) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of V

D

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

O

I

O

V

I

TJ = +25°C

∆V

O

V

I

V

I

TJ = +25°C
I

O

O

T

J

I

O

Q

TJ = +25°C-36mA
IO = 5mA to 1A - 0.05 0.5

Q

V

I

∆Vo/∆TI

N

O

f = 10Hz to 100kHz
T

A

f = 120Hz
∆V

TJ = +25°C

D

I

O
SC
PK

TJ = +25°C, VI = -35V - 300 - mA
TJ = +25°C-2.2-A

= 5mA to 1A, P

= -15.5V to -27V

≤ 15W

O

VI = -14.5V to -27V
Io = 1A

= -16V to -22V

V

I

Io = 1A

-11.5 -12 -12.5

- 12 120

-660

= -14.8V to -30V - 12 120
= -16V to -22V, Io = 1A - 12 120

= 5mA to 1.5A

= +25°C

= 250mA to 750mA

- 12 150

-475

= -15V to -30V - 0.1 1

= 5mA - -0.8 - mV/°C

= +25°C

= 10V

I

= 1A

- 200 - µV

54 60 - dB

-2-V

V

mV

mV

mA

Note:

1. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

12

due to heating e ffe cts mus t be t ak en

O

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7915A)

(V

= -23V, IO = 500mA, 0°C ≤T

I

≤ +125°C, C

J

=2.2µF, CO =1µF, unless otherwise specified.)

I

(Continued)

Parameter Symbol Conditions Min. Typ. Max. Unit

TJ = +25°C -14.7 -15 -15.3

Output Voltage V

Line Regulation (Note1) ∆V

Load Regulation (Note1) ∆V

Quiescent Current I
Quiescent Current Change ∆I
Temperature Coefficient of V

D

Output Noise Voltage V

Ripple Rejection RR

Dropout Voltage V
Short Circuit Current I

Peak Current I

O

I

O

V

I

TJ = +25°C

O

V

I

V

I

TJ = +25°C
I

O

O

T

J

I

O

TJ = +25°C-36mA

Q

IO = 5mA to 1A - 0.05 0.5

Q

V

I

∆Vo/∆TI

O

f = 10Hz to 100kHz

N

T

A

f = 120Hz
∆V

TJ = +25°C

D

I

O
SC
PK

TJ = +25°C, VI = -35V - 300 - mA
TJ = +25°C-2.2-A

= 5mA to 1A, P
= -18V to -30V

≤ 15W

O

VI = -17.5V to -30V
Io = 1A

= -20V to -26V

V

I

Io = 1A

-14.4 -15 -15.6

- 12 150

-675

= -17.9V to -30V - 12 150
= -20V to -26V, Io = 1A - 6 150

= 5mA to 1.5A

= +25°C

= 250mA to 750mA

- 12 150

-475

= -18.5V to -30V - 0.1 1
= 5mA - -0.9 - mV/°C

= +25°C

= 10V

I

= 1A

- 250 - µV

54 60 - dB

-2-V

V

mV

mV

mA

Note:

1. Load and line regulation are specified at constant junction temperature. Changes in V
into account separately. Pulse testing with low duty is used.

due to heating eff e cts mus t be t aken

O

13

MC79XX/MC79XXA/LM79XX

]

DtVlt[V]

A

Typical Perfomance Characteristics

5.1

5.05

Ou
tp

5

ut
Vo

4.95

lta
ge

4.9

[-
V

Output Voltage[-V]

4.85

4.8

-40 -25 0 25 50 75 100 125

TA, Ambient Temperature [oC]

Figure 1. Output Voltage

5

4.5
4

3.5
3

2.5
2

1.5
1

Quiescent Current [mA]

0.5
0

-40 -25 0 25 50 75 100 125

TA, Ambient Temperature [oC]

Vin=10V
Io=40mA

Vin=25V
Io=100mA

15
13

Lo

11

ad

9

Re
gul

7

ati

5

on

3

[m

1

V]

-1

Load Regulation[mV]

-3

-5

-40 -25 0 25 50 75 100 125

Io=1.5A

Io=0.75A

T

, Ambient Temperature [oC]

A

Figure 2. Load Regulation

4

3.5
3

2.5
2

1.5
1

Dropout Voltage [V]

0.5
0

-40-250255075100125

Io=1A

TA, Ambient Temperature [oC]

Figure 3. Quiescent Current

0.6

0.55

Sh

0.5

ort

0.45

0.4

Cir

0.35

cui

0.3

t

0.25

Cu

0.2

rre

0.15

0.1

nt

0.05

[A]

Short Circuit Current[A]

0

-0.05

-0.1

-40 -25 0 25 50 75 100 125

, Ambient Temperature [oC]

T

Figure 4. Dropout Voltage

Figure 5. Short Circuit Current

14

Typical Applications

2.2

F

- V

µµµµ

++

C

I

I

Input

2

1

MC79XX

KA79XX

LM79XX

µµµµ

F

1

CO

3

Output

- V

O

Figure 6. Negative Fixed output regulator

MC79XX/MC79XXA/LM79XX

+ 15V

- 15V

1

MC7812

KA7812

+

C1

C1

µµµµ

F

0.33

µµµµ

2.2

F

++

2

KA7912

MC7912

3

+

Co

2

µµµµ

1

F

1

µµµµ

F

Co

1

3

1N4001

*

1N4001

*

+12V

GND

-12V

Figure 7. Split powe r supply ( ±±±± 12V/1A)

Notes:

(1) To specify an output voltage, substitute voltage value for "XX "
(2) Required for stability. For valu e given, capacitor must be solid tantalum . If aluminium electronics are used, at least ten times

value shown should be selected. C

is required if regulator is located an appreciable distance from power supply filter.

I

(3) To improve transient response. If large capacitors are used, a high current diode from input to output (1N400l or similar)

should be introduced to protect the device from momentary input short circuit.

15

MC79XX/MC79XXA/LM79XX

Mechanical Dimensions

Package

9.90

±0.20

(8.70)

(1.70)

±0.20

9.20

±0.10

1.30

(1.46)

ø3.60

±0.10

TO-220

±0.10

2.80

(3.70)(3.00)

±0.20

15.90

(45°)

18.95MAX.

Dimensions in millimeters

4.50

±0.20

+0.10

1.30

–0.05

±0.20

13.08

[2.54

(1.00)

1.27

±0.10

2.54TYP

±0.20

]

10.00

±0.20

1.52

±0.10

0.80

±0.10

2.54TYP

±0.20

[2.54

±0.30

10.08

+0.10

0.50

–0.05

2.40

±0.20

]

16

Ordering Information

Product Number Output Voltage Tolerance Package Operating Temperature

LM7905CT ±4% TO-220 0 ~ +125°C

Product Number Output Voltage Tolerance Package O perating Temperature

MC7905CT
MC7906CT
MC7908CT
MC7909CT

±

MC7910CT
MC7912CT
MC7915CT
MC7918CT
MC7924CT

MC7905ACT

MC7915ACT

4%

TO-220 0 ~ +125°C

±2%MC7912ACT

MC79XX/MC79XXA/LM79XX

17

MC79XX/MC79XXA/LM79XX

DISCLAIMER

FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURT HER NOTICE TO ANY
PRODUCTS HEREI N TO IMPROVE RELIABILITY, FUNCTIO N OR DESIGN. FAIRCH IL D DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER
DOES IT CONVEY ANY LICENSE UNDER IT S PATENT RIGHTS, NOR THE RIGHTS OF OTHE RS.

LIFE SUPPORT POL I CY

FAIRCHILD’S PR ODUCTS ARE NOT AUTH ORIZED FOR USE AS C RITICAL COMPONENT S IN LIFE SUPPORT DE VICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein :

1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with

2. A critical component in any component of a life support
device or sy stem whose fai lure to perform can be
reasonably expec ted to cause the failur e of the life support
device or system, or to affect its safety or effec t iv ene ss .

instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.

www.fairchildsemi.com

11/12/02 0.0m 001

 2002 Fairchild Semiconductor Corporation

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