LM9070

Low-Dropout System Voltage Regulator with Keep-Alive

ON/OFF Control

General Description

The LM9070 is a 5V, 3% accurate, 250 mA low-dropout volt-

age regulator. The regulator features an active low delayed

reset output flag which can be used to reset a microproces-

sor system on turn-ON and in the event that the regulator

output falls out of regulation for any reason. An external ca-

pacitor programs a delay time interval before the reset out-

put can return high.

Designed for automotive application the LM9070 contains a

variety of protection features such as reverse battery,

over-voltage shutdown, thermal shutdown, input transient

protection and a wide operating temperature range.

A unique two-input logic control scheme is used to enable or

disable the regulator output. An ON/OFF input can be pro-

vided by an ignition switch derived signal while a second,

Keep-Alive input, is generated by a system controller. This

allows for a system to remain ON after ignition has been

switched OFF. The system controller can then execute a

power-down routine and after which command the regulator

OFF to a low quiescent current state (60 µA max).

Design techniques have been employed to allow the regula-

tor to remain operational and not generate false reset signals

when subjected to high levels of RF energy (300V/m from

2 MHz to 400 MHz).

Features

n Automotive application reliability

n 3% output voltage tolerance

n Insensitive to radiated RFI

n Dropout voltage less than 800 mV with 250 mA output

current

n Externally programmed reset delay interval

n Keep-alive feature with 2 logic control inputs

n 60V Load dump transient protection

n Thermal shutdown

n Short circuit protection and disable safety features

n Reverse battery protection

n Low OFF quiescent current, 50 µA maximum

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

n TO-263 and 20-pin power surface mount packages

n Lead form compatible with TLE4267 TO-220 regulator

(package TA07D)

7-Lead TO-263

Surface Mount Package

DS012831-1

Backside metal is internally connected to ground.

Order Number LM9070S

See NS Package Number TS7B

20-Pin SO Package

DS012831-2

Order Number LM9070M

See NS Package Number M20B

December 1999

© 1999 National Semiconductor Corporation

DS012831

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