D
D
E
E
S
S
C
C
R
R
I
I
P
P
T
T
I
I
O
O
N
N
The
LM
317 are adjustable 3-terminal positive-voltage regulators capable of supplying 1.5A over
a differential voltage range of 3V to 40V. They are exceptionally easy to use and require only two
external resistors to set the output voltage. Both input and output regulation is better than
standard fixed regulators.
In addition to higher performance than fixed regulators, these regulators offer full overload
protection available only in integrated circuits. Included on the chip are current limit, thermal
overload protection, and safe-area protection. All overload protection circuit remains fully
functional even if the adjustment terminal is disconnected. Normally, no capacitors are needed
unless the device is situated far from the input filter capacitors in which case an input bypass is
needed. An optional output capacitor can be added to improve transient response.
The primary applications of each of these regulators is that of a programmable output regulator,
but by connecting a fixed resistor between adjustment terminal and the output terminal, each
device can be used as a precision current regulator. Even though the regulator is floating and
sees only the input-to-output differential voltage, use of these devices to regulate output voltages
that would cause the maximum-rated differential voltage to be exceeded if the output became
shorted is not recommended
FEATURES
!
Output Voltage Range Adjustable from1.2 V to 37V
!
Output Current Capability of 1.5A Max
!
Input Regulation Typically 0.01% Per Input-Volt
Change
!
Output Regulation Typically 0.1%
!
Peak Output Current Constant over Temperature
Range of Regulator
!
Popular 3-Lead TO-220 AB Package
!
Ripple Rejection Typically 80 dB
ABSOLUTE MAXIMUM RATINGS
Input-Output Voltage Differential V
I
- V
O
Operating Junction Temperature Range
Continuous total dissipation at 25
Continuous total dissipation at (or below ) 25
Storage Temperature
Lead Temperature1.6 mm from case for 10 seconds
40V
℃
0
℃
to +125
2000mW
℃
free-air temperature
℃
case temperature
15W
–65
℃
to +150
℃
℃
260
RECOMMENDED OPERATING CONDITIONS
MIN
10
0
MAX
1500
70
℃
UNIT
mA
OUTPUT CURRENT, I
O
OPERATING VIRTUAL JUNCTION TEMPERATURE,T
J
Wing Shing Computer Components Co., (H.K.)Ltd.
Homepage:
http://www.wingshing.com
Tel:(852)2341 9276 Fax:(852)2797 8153
E-mail: wsccltd@hkstar.com
3-TERMINAL ADJUSTABLE REGULATORS
TO-220 PACKAGE
LM317T
INPUT
OUTPUT
ADJUSTMENT
A
D
I
LM317
A
O
I
TO-92
LM317LZ
INPUT
OUTPUT
ADJ