( )

OUT

ADJ

R

V

= 1.25 V

I

R

R

2

2

1

1

æ

ö

+

+

ç

÷

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An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.

LM117, LM317-N

SNVS774Q – MAY 2004 – REVISED JUNE 2020

LM117, LM317-N Wide Temperature Three-Pin Adjustable Regulator

1

1 Features

1

•

For a newer drop-in alternative, see the LM317

•

Typ. 0.1% load regulation

•

Typ. 0.01%/V line regulation

•

1.5-A output current

•

Adjustable output down to 1.25 V

•

Current limit constant with temperature

•

80-dB ripple rejection

•

Short-circuit protected output

•

−55°C to 150°C operating temperature range

(LM117)

2 Applications

•

Multifunction printers

•

AC drive power stage modules

•

Electricity meters

•

Servo drive control modules

•

Merchant network and server PSU

Typical Application

*Needed if device is more than 6 inches from filter

capacitors.

†Optional—improves transient response

††

3 Description

The LM117 and LM317-N series of adjustable 3-pin

positive voltage regulators are capable of supplying in

excess of 1.5 A over a 1.25-V to 37-V output range

and

a

wide

temperature

range.

They

are

exceptionally easy to use and require only two

external resistors to set the output voltage. Further,

both line and load regulation are better than standard

fixed regulators.

The

LM117

and

LM317-N

offer

full

overload

protection such as current limit, thermal overload

protection and safe area protection. All overload

protection circuitry remains fully functional even if the

adjustment terminal is disconnected.

Typically, no capacitors are needed unless the device

is situated more than 6 inches 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 adjustment terminal can be

bypassed to achieve very high ripple rejection ratios

that are difficult to achieve with standard 3-terminal

regulators.

Because the regulator is floating and detects only the

input-to-output differential voltage, supplies of several

hundred volts can be regulated as long as the

maximum input-to-output differential is not exceeded.

That is, avoid short-circuiting the output.

By

connecting

a

fixed

resistor

between

the

adjustment pin and output, the LM117 and LM317-N

can be also used as a precision current regulator.

Supplies with electronic shutdown can be achieved

by clamping the adjustment terminal to ground, which

programs the output to 1.25 V where most loads draw

little current.

For applications requiring greater output current, see

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

sheets. For the negative complement, see the LM137

series data sheet.

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

LM117

TO-3 (2)

38.94 mm x 25.40 mm

TO (3)

8.255 mm × 8.255 mm

LM317-N

TO-3 (2)

38.94 mm x 25.40 mm

TO-220 (3)

14.986 mm × 10.16 mm

TO-263 (3)

10.18 mm × 8.41 mm

SOT-223 (4)

6.50 mm × 3.50 mm

TO (3)

8.255 mm × 8.255 mm

TO-252 (3)

6.58 mm × 6.10 mm

(1) For all available packages, see the orderable addendum at

the end of the data sheet.