ST1534A

Features:

GLITCH FREE TRANSITION BETWEEN INPUT SOURCES
INTERNAL LOGIC SELECTS INPUT SOURCE
GATE DRIVE FOR EXTERNAL PMOS BYPASS SWITCH
5V DETECTOR WITH HYSTERESIS
1% 3.3V REGULATED OUTPUT VOLTAGE
500mA GUARANTEED OUTPUT CURRENT
OPERATING TEMPERATURE RANGE FROM 0°C TO 85°C 
AVAILABLE IN P² PAK PACKAGE
PPAK AND SO-8 PACKAGES CAN BE
   AVAILABLE ON REQUEST 


Application

NETWORK INTERFACE CARDS
PCMCIA/PCI INTERFACE CARDS
DESKTOP COMPUTERS
POWER SUPPLY WITH MULTIPLE INPUT SOURCES


Pinout




Specifications

Symbol	Parameter2	Value	Unit
VI	DC Input Voltage	-0.3 to 7	V
VSHDN	Shutdown Input Voltage	-0.3 to 7	V
IO	Output Current	Internally limited	mA
Tstg	Storage Temperature Range	-40 to +125	°C
Top	Operating Junction Temperature Range	0to+85	°C

Description

The ST1534A is intended for application such as power managed PCI and network interface cards (NICs), where operations from 3.3V VAUX supply may be required when the 5V supply has been shut down.

During regular operation of the ST1534A, 3.3V power for the PCI card is provided by the internal LDO regulator, generated from 5V supply. When the 5V V_AUX  is available,the IC connects this supply directly toits output using an external P-Channel FET. This ensures an uninterrupted 3.3V outevenif VIN falls out of specification.