LM9074

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 system 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 provided 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 regulator 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 n n n n n n n n n n n Automotive application reliability 3% output voltage tole...