SC1543 Datasheet | SEMTECH

DESCRIPTION The SC1543 provides a glitch free 3.3V output when one of two 3.3V input sources is present. It does not require external logic to sequence from one input source to the other. Whenever VIN1 exceeds a predetermined threshold value the internal MOSFET connects it’s source voltage to the output. If the input at VIN1 is below the threshold another internal MOSFET connects VIN2 to the output. If both inputs are at 3.3V then VIN1 will be connected to the output. The SC1543 is designed to provide 400m A from the main input (VIN1) and 200m A from the secondary input (VIN2). A very low quiescent current of 10µA in shutdown mode reduces power dissipation. The internal logic and control circuit detects the voltage levels of VIN1 and VIN2, and pares them to an input reference voltage of 2.9V. An internally controlled period of switch overlap ensures that the transition between supplies is as glitch-free as possible. The SC1543 is available in an MSOP-8 surface mount package. Features - = - = - = - = - = Glitch free transitions between inputs Internal logic selects appropriate input 400m A load current capability from main input Low power shutdown mode Industrial temperature range APPLICATIONS - = Mini PCI cards - = Peripheral cards - = Instantly available personal puters (IAPCs) ORDERING INFORMATION Part Number (1) Package MSOP-8 SC1543IMSTR Note: (1) Only available in tape and reel packaging. A reel contains 2500 devices. APPLICATION CIRCUIT SHUTDOWN U1 3.3V IN 1 2 3 3.3VAUX IN 4 VIN1 VIN1 VIN2 VIN2 SC1543 CIN1 1u F CIN2 1u F COUT 10u F SHDN VOUT VOUT GND 8 7 6 5 3.3V OUT 1 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 400m A/200m A Dual 3.3V Smart Power Switch PRELIMINARY - October 9, 2000 ABSOLUTE MAXIMUM RATINGS Parameter Input Supply Voltage Output Current From: VIN1 VIN2 Operating Ambient Temperature Range Operating Junction Temperature Range Storage Temperature Range Lead Temperature (Soldering, 10 Sec.) Thermal Impedance Junction to...