LM117, LM317-N

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SNVS774L – MAY 2004 – REVISED FEBRUARY 2011

LM117/LM317A/LM317-N 3-Terminal Adjustable Regulator

Check for Samples: LM117, LM317-N

Normally, no capacitors are needed unless the device

1

FEATURES

is situated more than 6 inches from the input filter

2

•

Specified 1% Output Voltage Tolerance

capacitors in which case an input bypass is needed.

(LM317A)

An optional output capacitor can be added to improve

•

Specified Max. 0.01%/V Line Regulation

transient response. The adjustment terminal can be

bypassed to achieve very high ripple rejection ratios

(LM317A)

which are difficult to achieve with standard 3-terminal

•

Specified Max. 0.3% Load Regulation (LM117)

regulators.

•

Specified 1.5A Output Current

Besides replacing fixed regulators, the LM117 is

•

Adjustable Output Down to 1.2V

useful in a wide variety of other applications. Since

•

Current Limit Constant With Temperature

the regulator is “floating” and sees only the input-to-

output

differential

voltage,

supplies

of

several

•

hundred volts can be regulated as long as the

•

80 dB Ripple Rejection

maximum input to output differential is not exceeded,

•

Output is Short-Circuit Protected

i.e., avoid short-circuiting the output.

Also, it makes an especially simple adjustable

DESCRIPTION

switching regulator, a programmable output regulator,

The LM117 series of adjustable 3-terminal positive

or by connecting a fixed resistor between the

voltage regulators is capable of supplying in excess

adjustment pin and output, the LM117 can be used

of 1.5A over a 1.2V to 37V output range. They are

as a precision current regulator. Supplies with

exceptionally easy to use and require only two

electronic shutdown can be achieved by clamping the

external resistors to set the output voltage. Further,

adjustment terminal to ground which programs the

both line and load regulation are better than standard

output to 1.2V where most loads draw little current.

fixed regulators. Also, the LM117 is packaged in

standard

transistor

packages

which

are

easily

For applications requiring greater output current, see

mounted and handled.

LM150 series (3A) and LM138 series (5A) data

sheets. For the negative complement, see LM137

In

addition

to

higher

performance

than

fixed

series data sheet.

regulators, the LM117 series offers full overload

protection available only in IC's. Included on the chip

are current limit, thermal overload protection and safe

area protection. All overload protection circuitry

remains fully functional even if the adjustment

terminal is disconnected.

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

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PRODUCTION DATA information is current as of publication date.

Copyright © 2004–2011, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.