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