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ULTRALOW-POWER REAL-TIME CLOCK EXTENDS BATTERY LIFE

NXP Semiconductor’s PCF2123 real-time clock has an operating current of less than 100 nA, or 0.15 µW, on a 1.5V power supply. The 3X3X1-mm package includes a freely programmable alarm-and-timer function that can generate a wake-up signal on an interrupt pin. A programmable offset register supports fine-tuning of the clock and frequency adjustment.

The seconds, minutes, hours, days, weekdays, months, and years registers are coded in BCD (binary-coded-decimal) format. Data from the real-time clock is accessible serially through an SPI (serial-peripheral-interface) bus with a maximum data rate of 6.25 Mbps. The CMOS-based device uses a low-power, 32.768-kHz quartz oscillator that you can calibrate using an onchip calibration register. The device requires no other external parts. The PCF2123 real-time clock is available now for 55 cents (high volumes).

NXP Semiconductor, www.nxp.com