LM9072

Dual Tracking Low-Dropout System Regulator

General Description

The LM9072 is a high performance voltage regulator system

with operational and protection features that address many

requirements of automotive applications. Two regulated out-

puts are provided. The main regulator provides a precision

2% maximum tolerance 5V output at 350 mA with a low drop-

out characteristic. The second regulator provides a 5V out-

put that tracks the main regulator output voltage within 1.5%

with load currents up to 80 mA. The tracking output is ideal

for use in powering remotely located sensors with outputs

that are ratiometric to the main system supply. This output is

fully protected from short circuits to ground or the unregu-

lated input supply (ignition or battery potentials in automotive

applications).

The LM9072 also contains a programmable delayed system

reset output. Two control inputs are provided. An ON/OFF in-

put intended for connection to an ignition switch, and a Keep

Alive input to allow a system to remain powered after ignition

has been switched OFF.

For EMC concerns the LM9072 remains fully operational

and does not generate false rest signals while subjected to,

1 MHz to 400 MHz bulk current injection signals greater than

100 mA on the input supply and tracking output lines.

Features

n Two 5V regulated outputs:

— 350 mA, 2% Main output

— 80 mA, 1.5% Tracking output

n Good EMI (1 MHz to 400 MHz, BCI) immunity

n Separate ON/OFF and Keep-Alive control inputs

n Less than 100 µA quiescent current in OFF state

n Programmable delayed reset output

n Input transient protection over 60V to −45V

n Tracking output protected from shorts to battery

n Less than 1V dropout at full load

n −40˚C to +125˚C operating temperature range

n Surface mount TO-263 Power Package and Standard

TO-220 power package

Typical Applications

n Automotive module supply power conditioning

n Remote sensor biasing

n Ratiometric to supply sensor detection

n Continuous operation for save routines and EPROM

programming after power down command

n Safety related systems — EMC operational

Connection Diagrams and Ordering Information

9-Lead TO-263

Surface Mount Power Package

DS012906-2

Backside metal is internally connected to ground.

Order Number LM9072S

See NS Package Number TS9A

9-Lead TO-220 Package

DS012906-3

Tab is internally connected to ground.

Order Number LM9072T

See NS Package Number TA9A

December 1999

© 1999 National Semiconductor Corporation

DS012906

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