Power Sequencers Eye Multi-Voltage Systems

Designed for processor sub-systems and multi-voltage systems, the X80200 family of power sequencers provides power-up timing between primary and secondary voltage supplies. The devices can independently sequence three separate voltage supply sources in various ramp-up and ramp-down timing schemes and can support supply voltages from 0.9V to 5V. They integrate three drivers to enable/disable external n-channel MOSFET switches, voltage monitors, power up/down sequencing logic, and two-wire interface circuits. The devices employ a core voltage up-first, down-last sequencing logic scheme, a feature required by new microcontrollers, ASICs and FPGAs. Up to eight devices can operate on a single two-wire bus for sequencing up to 24 supplies. Available in 20-lead TSSOPs, prices start at $2.40 each/1,000. XICOR INC., Milpitas, CA. (408) 546-3317.