1.5 A Adjustable Output,
Positive Voltage Regulator
The LM317 is an adjustable 3–terminal positive voltage regulator
capable of supplying in excess of 1.5 A over an output voltage range of
1.2 V to 37 V. This voltage regulator is exceptionally easy to use and
requires only two external resistors to set the output voltage. Further, it
employs internal current limiting, thermal shutdown and safe area
compensation, making it essentially blow–out proof.
The LM317 serves a wide variety of applications including local, on
card regulation. This device can also be used to make a programmable
output regulator, or by connecting a fixed resistor between the
adjustment and output, the LM317 can be used as a precision current
regulator.
• Output Current in Excess of 1.5 A
• Output Adjustable between 1.2 V and 37 V
• Internal Thermal Overload Protection
• Internal Short Circuit Current Limiting Constant with Temperature
• Output Transistor Safe–Area Compensation
• Floating Operation for High Voltage Applications
• Available in Surface Mount D
2
PAK, and Standard 3–Lead Transistor
Package
• Eliminates Stocking many Fixed Voltages
Standard Application
** C
in
is required if regulator is located an appreciable distance from power supply filter.
** C
O
is not needed for stability, however, it does improve transient response.
Since I
Adj
is controlled to less than 100 µA, the error associated with this term is
negligible in most applications.
V
out
1.25 V 1
R
2
R
1
I
Adj
R
2
LM317
V
in V
out
R
1
240
R
2
Adjust
I
Adj
C
in
*
0.1 µF
+
C
O
**
1.0 µF
ON Semiconductor
 Semiconductor Components Industries, LLC, 2002
January, 2002 – Rev. 3
1 Publication Order Number:
LM317/D
SEMICONDUCTOR
TECHNICAL DATA
THREE–TERMINAL
ADJUSTABLE POSITIVE
VOLTAGE REGULATOR
Device
Operating
Temperature Range Package
T SUFFIX
PLASTIC PACKAGE
CASE 221A
ORDERING INFORMATION
LM317BT
LM317BD2T
Insertion Mount
Surface Mount
LM317T
LM317D2T
T
J
= 0° to +125°C
Insertion Mount
Surface Mount
T
J
= –40° to +125°C
Pin 1. Adjust
2. V
out
3. V
in
D2T SUFFIX
PLASTIC PACKAGE
CASE 936
(D
2
PAK)
Heatsink surface (shown as terminal 4 in
case outline drawing) is connected to Pin 2.
3
1
2
Heatsink surface
connected to Pin 2.
LM317
3
1
2