RTCs Require Little Current

Specifying a quiescent current of 0.25 µA, the S-35180A and S-35380A real-time clocks (RTCs) assume position as the industry's lowest current clock devices. Both have a minimum time keeping voltage of 1.1V with an operating range of 1.3V to 5.5V and feature a clock-adjustment function that enables deviation correction in the oscillator at a minimum resolution of 1 ppm. For systems operating on a backup battery, a free register in the clock can sub as a backup-memory function. The S-35180A is available with a 3-wire CMOS interface, and the S-35380A provides an I2C interface. In either 8-pin SOPs or TSSOPs, prices are $0.60 and $0.65 each/10,000, respectively. SEIKO INSTRUMENTS USA INC., Torrance, CA. (310) 517-7700.