General description

The PCF8564A is a CMOS1 real-time clock and calendar optimized for low power consumption. A programmable clock output, interrupt output and voltage low detector are also provided. All addresses and data are transferred serially via the two-line bidirectional I2C-bus. Maximum bus speed is 400 kbit/s. The built-in word address register is incremented automatically after each written or read data byte.

Features and benefits

■ Provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal

■ Wide clock operating voltage: 1.0 V to 5.5 V

■ Low back-up current typical 250 nA at 3.0 V and 25 °C

■ 400 kHz two-wire I2C interface (1.8 V to 5.5 V)

■ Low-voltage detector

■ Alarm and timer functions

■ Two integrated oscillator capacitors

■ Programmable clock output for peripheral devices (32.768 kHz, 1.024 kHz, 32 Hz, and 1 Hz)

■ Internal Power-On Reset (POR)

■ I2C slave address: read A3h, write A2h

Applications

■ Timing devices

◆ Time of the day tracking

◆ Process timing

◆ Alarm

■ Portable instruments

■ Electronic metering

■ Battery powered products