LM79MXX Series 3-Terminal Negative Regulators
September 2001
LM79MXX Series
3-Terminal Negative Regulators
General Description
The LM79MXX series of 3-terminal regulators is available
with fixed output voltages of −5V, −12V, and −15V. These
devices need only one external component — a compensa-
tion capacitor at the output. The LM79MXX series is pack-
aged in the TO-220 power package, and is capable of sup-
plying 0.5A of output current.
These regulators employ internal current limiting, safe area
protection, and thermal shutdown for protection against vir-
tually all overload conditions.
Low ground pin current of the LM79MXX series allows out-
put voltage to be easily boosted above the preset value with
a resistor divider. The low quiescent current of these devices
with a specified maximum change with line and load ensures
good regulation in the voltage boosted mode.
For output voltage other than −5V, −12V, and −15V the
LM137 series provides an output voltage range from −1.2V
to −57V.
Features
n
n
n
n
Thermal, short circuit and safe area protection
High ripple rejection
0.5A output current
4% tolerance on preset output voltage
Connection Diagram
TO-220 Plastic Package (T)
DS010483-7
Front View
Order Number LM79M05CT, LM79M12CT or LM79M15CT
See NS Package Number T03B
© 2001 National Semiconductor Corporation
DS010483
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LM79MXX Series
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Input Voltage
V
O
= −5V
V
O
= −12V, −15V
Input/Output Differential
V
O
= −5V
V
O
= −12V, −15V
−25V
−35V
25V
30V
Power Dissipation (Note 2)
Operating Junction
Temperature Range
Storage Temperature Range
Lead Temperature
(Soldering, 10 sec.)
ESD Susceptibility
Internally Limited
0˚C to +125˚C
−65˚C to +150˚C
230˚C
TBD
Electrical Characteristics LM79M05C
Conditions unless otherwise noted: I
OUT
= 350mA, C
IN
= 2.2µF, C
OUT
= 1µF, 0˚C
≤
T
J
≤
+125˚C
Part Number
Output Voltage
Input Voltage (Unless Otherwise Specified)
Symbol
V
O
Parameter
Output Voltage
Conditions
T
J
= 25˚C
5mA
≤
I
OUT
≤
350mA
∆V
O
Line Regulation
T
J
= 25˚C (Note 3)
Min
−4.8
−4.75
(−25
≤
V
IN
≤
−7)
8
(−25
≤
V
IN
≤
−7)
2
(−18
≤
V
IN
≤
− 8)
∆V
O
I
Q
∆I
Q
Load Regulation
Quiescent Current
Quiescent Current
Change
With Load,
5mA
≤
I
OUT
≤
350mA
V
n
Output Noise Voltage
Ripple Rejection
Dropout Voltage
I
OMAX
Peak Output Current
Average Temperature
Coefficient of
Output Voltage
T
A
= 25˚C,
10Hz
≤
f
≤
100Hz
f = 120Hz
T
J
= 25˚C, I
OUT
= 0.5A
T
J
= 25˚C
I
OUT
= 5mA,
0˚C
≤
T
J
≤
100˚C
−0.4
mV/˚C
54
66
(−18
≤
V
IN
≤
−8)
1.1
800
V
mA
dB
150
0.4
mA
µV
T
J
= 25˚C, (Note 3)
5mA
≤
I
OUT
≤
0.5A
T
J
= 25˚C
With Input Voltage
(−25
≤
V
IN
≤
−8)
1
2
0.4
mA
mA
30
100
mV
30
mV
50
mV
LM79M05C
−5V
−10V
Typ
−5.0
Max
−5.2
−5.25
V
V
Units
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2
LM79MXX Series
Electrical Characteristics LM79M12C, LM79M15C
Conditions unless otherwise noted: I
OUT
= 350mA, C
IN
= 2.2µF, C
OUT
= 1 µF, 0˚C
≤
T
J
≤
+125˚C
Part Number
Output Voltage
Input Voltage (Unless Otherwise Specified)
Symbol
V
O
Parameter
Output Voltage
Conditions
T
J
= 25˚C
5 mA
≤
I
OUT
≤
350mA
∆V
O
Line Regulation
T
J
= 25˚C (Note 3)
Min
−11.5
−11.4
5
3
(−25
≤
V
IN
≤
− 15)
∆V
O
I
Q
∆I
Q
Load Regulation
Quiescent Current
Quiescent Current
Change
With Load,
5mA
≤
I
OUT
≤
350mA
V
n
Output Noise
Voltage
Ripple Rejection
Dropout Voltage
I
OMAX
Peak Output
Current
Coefficient of
Output Voltage
Note 1:
Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.
Note 2:
Refer to Typical Performance Characteristics and Design Considerations for details.
Note 3:
Regulation is measued at a constant junction temperature by pulse testing with a low duty cycle. Changes in output voltage due to heating effects must be
taken into account.
LM79M12C
−12V
−19V
Typ
−12.0
Max
−12.5
−12.6
80
50
240
3
0.4
(−30
≤
V
IN
≤
−14.5)
0.4
400
54
70
(−25
≤
V
IN
≤
−15)
T
J
= 25˚C, I
OUT
= 0.5A
T
J
= 25˚C
1.1
800
54
Min
−14.4
−14.25
LM79M15C
−15V
−23V
Typ
−15.0
Max
−15.6
−15.75
5
3
(−28
≤
V
IN
≤
−18)
30
1.5
(−30
≤
V
IN
≤
−27)
0.4
400
70
1.1
800
mA
µV
dB
V
mA
240
3
0.4
mV
mA
mA
80
50
V
V
mV
mV
Units
(−27
≤
V
IN
≤
−14.5)
(−30
≤
V
IN
≤
−14.5)
(−30
≤
V
IN
≤
−10.5)
(−30
≤
V
IN
≤−17.5)
T
J
= 25˚C, (Note 3)
5mA
≤
I
OUT
≤
0.5A
T
J
= 25˚C
With Input Voltage
30
1.5
T
A
= 25˚C,
10Hz
≤
f
≤
100Hz
f = 120Hz
(−30
≤
V
IN
≤
−17.5)
Average Temperature I
OUT
= 5mA,
0˚C
≤
T
J
≤
100˚C
−0.8
−1.0
mV/˚C
Typical Performance Characteristics
Output Voltage vs. Temperature
Ripple Rejection
DS010483-11
DS010483-12
3
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