LM9074 datasheet(7/9 Pages) NSC

No de pièce	LM9074

Description	System Voltage Regulator with Keep-Alive ON/OFF

PDF	9 Pages

Scroll/Zoom	100%

Fabricant	NSC [National Semiconductor (TI)]

Site Internet	http://www.national.com

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7 / 9 page

Application Information (Continued)

MICROPROCESSOR SYSTEM REGULATOR WITH

KEEP-ALIVE INTERVAL AT TURN-OFF

The following circuit illustrates a system application utilizing

both of the logic control inputs of the LM9074. Closing the

ON/OFF switch powers ON the system. Once powered, the

system controller sets the Keep-Alive line low. The NPN

transistor is used only to signal the controller that the ON/

OFF switch has been opened and the system is to be turned

OFF. Upon detecting this high level at the ON/OFF Sense in-

put line, the controller can then perform a power down rou-

tine. The system will remain fully powered until the controller

commands total shut down by taking the Keep-Alive line

high. The system then shuts OFF and reverts to a very low

current drain standby condition until switched back on.

DS101305-26

LM9074 Fiches technique(PDF) 7 Page - National Semiconductor (TI)