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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.

LM138QML

SNVSAA9 – OCTOBER 2017

LM138QML Military Grade 5-A Adjustable Output Linear Regulator

1

1 Features

1

•

Manufactured and Tested per Texas Instruments

Military Grade Flow

•

Specified 7-A Peak Output Current

•

Specified 5-A Output Current

•

Wide Temperature Range –55°C to 150°C

•

Adjustable Output Down to 1.2 V

•

Specified Thermal Regulation

•

Current Limit Constant With Temperature

•

•

Output is Short-Circuit Protected

2 Applications

•

Adjustable Power Supplies

•

Constant Current Regulators

•

Battery Chargers

3 Description

The

LM138QML

adjustable

3-terminal

positive

voltage regulator is capable of supplying in excess of

5 A over a 1.2-V to 32-V output range. The device is

exceptionally easy to use and requires only two

resistors to set the output voltage. Careful circuit

design has resulted in outstanding load and line

regulation—comparable to many commercial power

supplies.

A unique feature of the LM138QML device is time-

dependent current limiting. The current limit circuitry

allows peak currents of up to 12 A to be drawn from

the regulator for short periods of time. This allows the

LM138QML device to be used with heavy transient

loads and speeds start-up under full-load conditions.

Under sustained loading conditions, the current limit

decreases to a safe value protecting the regulator.

Also included on the chip are thermal overload

protection and safe area protection for the power

transistor. Overload protection remains functional

even

if

the

adjustment

pin

is

accidentally

disconnected.

Normally, 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 output capacitor can be added to improve

transient response, while bypassing the adjustment

pin will increase the regulator's ripple rejection.

Besides

replacing

fixed

regulators

or

discrete

designs, the LM138QML is useful in a wide variety of

other applications. Since 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 maximum input to output differential is not

exceeded; that is, do not short-circuit output to

ground.

Device Information(1)

PART NUMBER

GRADE

PACKAGE

LM138K-MIL

Military

TO-3 (2)

LM138KG-MD8

Military

Die

LM138KG-MW8

Military

Wafer

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

the end of the data sheet.

Typical Application Circuit