ICs Switch Power From Main To Backup Sources

Tooled for devices that employ automatic backup power switching, the S-8424A and S-8424B ICs pack all the functions needed for such switching assignments in a single, eight-pin TSSOP. Delivering a sequence of main power detection and automatic switching to backup power supplies, the S-8424A and S-8424B include two voltage regulators, a power supply switch and controller, and independently selectable output voltages from 2.3V to 5.4V in 0.1V steps. The S-8424A includes three power supply voltage detectors (CS, PREEND and RESET) and has a quiescent current of 15 µA during operation. The S-8424B integrates two voltage detectors (CS and RESET) and has a 13 µA quiescent current. Both series draw a 2.1 µA quiescent current during backup. Price is $0.83 each/10,000. SEIKO INSTRUMENTS, Torrance, CA. (800) 934-9334.