Vishay Siliconix Intros Si9137 Power Supply ControllerMay 27, 2002 by Jeff Shepard
Vishay Intertechnology Inc. (Malvern, PA) introduced its new Si9137 power supply controller, which provides 95 percent conversion efficiency, synchronous rectification, and helps maximize battery life in portable products, including notebooks, PDAs, mobile communicators and portable displays.
The chip provides fixed 3.3V and 5V outputs, and a 500mA adjustable 5V to 12V output set by an external resistor divider. Additional features include programmable output sequencing; a 3.3V reference for precision analog circuits; a 5V, 30mA linear regulator output for MOSFET gate voltage control; and output current limit, over-voltage and under-voltage protection features. To minimize power consumption, the Si9137 operates in a power-saving, pulse-skipping mode at light loads, and an operational frequency fixed at 300kHz to reduce noise.
The 28-pin SSOP device has an input range of 5.5V to 30V, an output-voltage regulation of ±3 percent, and operates from 0 to 90 degrees C. The IC also provides selectable, pre-programmed, power-up sequencing; power-good signal with delay; internal frequency compensation networks; and automatic boot-strapping.