LM9074 System Voltage Regulator with Keep-Alive ON/OFF Control
PRELIMINARY
January 2000
LM9074
System Voltage Regulator with Keep-Alive ON/OFF
Control
General Description
The LM9074 is a 5V, 3% accurate, 180 mA NPN voltage
regulator. The regulator features an active low delayed reset
output flag which can be used to reset a microprocessor sys-
tem on turn-ON and in the event that the regulator output
falls out of regulation for any reason. An external capacitor
programs a delay time interval before the reset output can
return high.
Designed for automotive application the LM9074 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 碌A(chǔ) 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
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Automotive application reliability
3% output voltage tolerance
Insensitive to radiated RFI
Dropout voltage less than 2.5V with 180 mA output
current
Externally programmed reset delay interval
Keep-alive feature with 2 logic control inputs
60V Load dump transient protection
Thermal shutdown
Short circuit protection and disable safety features
Reverse battery protection
Low OFF quiescent current, 60 碌A(chǔ) maximum
Wide operating temperature range 鈭?0藲C to +125藲C
Connection Diagrams and Ordering Information
14-Pin SO Package
(Top View)
DS101305-2
Order Number LM9074M
See NS Package Number M14A
漏 2000 National Semiconductor Corporation
DS101305
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