ST1534A

www.DataSheet4U.com ST1534A 500mA SMART LDO s s s s s s s s s 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 P2PAK PACKAGE PPAK AND SO-8 PACKAGES CAN BE AVAILABLE ON REQUEST P2PAK PPAK SO-8 APPLICATIONS s s s s NETWORK INTERFACE CARDS PCMCIA/PCI INTERFACE CARDS DESKTOP COMPUTERS POWER SUPPLY WITH MULTIPLE INPUT SOURCES DESCRIPTION The ST1534A is intended for application such as power managed PCI and network interface cards (NICs), where operations from 3.3V VAUX supply SCHEMATIC DIAGRAM VIN may be required when the 5V supply has been shut down. During regular operation, 3.3V power for the PCI card is provided by the internal LDO regulator, generated from 5V supply. When the 5V VAUX is available, the IC connects this supply directly to its output using an external P-Channel FET. This ensures an uninterrupted 3.3V out even if VIN falls out of specification. When both supplies are available simultaneously, the drive pin DR will be pulled high, turning off the PMOS switch. The device is available in the popular 5 leads P2PAK and PPAK + 5V Detect DR Rpull_down VIN Reference + - Error Amp VOUT GND April 2003 1/15 ST1534A ABSOLUTE MAXIMUM RATINGS Symbol VI VSHDN IO Tstg Top DC Input Voltage Shutdown Input Voltage Output Current Storage ...