lm7915c National Semiconductor Corporation, lm7915c Datasheet - Page 3

• Manufacturer Part Number: lm7915c
• Description: 3-terminal Negative Regulators
• Manufacturer: National Semiconductor Corporation

I
V
I
Symbol
Q
OMAX
I
Conditions unless otherwise noted: I
n
Electrical Characteristics
Q
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 measured 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.
Design Considerations
The LM79XX fixed voltage regulator series has thermal
overload protection from excessive power dissipation, inter-
nal short circuit protection which limits the circuit’s maximum
current, and output transistor safe-area compensation for
reducing the output current as the voltage across the pass
transistor is increased.
Although the internal power dissipation is limited, the junc-
tion temperature must be kept below the maximum specified
temperature (125˚C) in order to meet data sheet specifica-
tions. To calculate the maximum junction temperature or
heat sink required, the following thermal resistance values
should be used:
Solving for T
Where:
TO-220
Package
T
T
T
P
J
J
A
D
= T
= T
= Junction Temperature
= Ambient Temperature
= Power Dissipation
A
A
Quiescent Current
Quiescent Current
Change
Output Noise Voltage
Ripple Rejection
Dropout Voltage
Peak Output Current
Average Temperature
Coefficient of
Output Voltage
Input Voltage (unless otherwise specified)
+ P
+ P
J
:
D JA
D
(
Parameter
˚C/W
Typ
3.0
JC
JC
(without heat sink)
+
CA
Output Voltage
Part Number
) or
˚C/W
Max
5.0
JC
OUT
5mA
250mA
T
With Line
With Load, 5mA
T
f = 120 Hz
T
T
I
0 C
OUT
J
A
J
J
˚C/W
= 500mA, C
Typ
= 25˚C
= 25˚C, I
= 25˚C
= 25˚C, 10Hz
60
JA
= 5mA,
(Continued)
T
I
J
OUT
Conditions
I
OUT
100˚C
OUT
˚C/W
Max
1.5A
IN
40
JA
= 1A
750mA
= 2.2µF, C
I
OUT
f
100Hz
3
1A
OUT
JA
JC
CA
CS
SA
= 1µF, 0˚C
(−30
Min
54
(−25
= Junction-to-Ambient Thermal Resistance
= Junction-to-Case Thermal Resistance
= Case-to-Ambient Thermal Resistance
= Case-to-Heat Sink Thermal Resistance
= Heat Sink-to-Ambient Thermal Resistance
LM7912C
−12V
−19V
V
−0.8
Typ
300
V
1.5
1.1
2.2
15
70
IN
5
IN
T
−14.5)
J
−15)
Max
200
0.5
0.5
75
3
+125˚C, Power Dissipation
Min
54
(−30 V
(−30
LM7915C
−15V
−23V
V
−1.0
Typ
375
1.5
1.1
2.2
IN
15
70
5
IN
−17.5)
−17.5)
Max
200
0.5
0.5
75
3
www.national.com
1.5W.
mV/˚C
Units
mV
mV
mA
mA
mA
µV
dB
V
V
V
A