1. General description
The PCF8564A is a CMOS
1
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
I
2
C-bus. Maximum bus speed is 400 kbit/s. The built-in word address register is
incremented automatically after each written or read data byte.
2. 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 I
2
C 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
1Hz)
Internal Power-On Reset (POR)
I
2
C slave address: read A3h, write A2h
3. Applications
Timing devices
Time of the day tracking
Process timing
Alarm
Portable instruments
Electronic metering
Battery powered products
PCF8564A
Real time clock and calendar
Rev. 3 — 26 August 2013 Product data sheet
1. The definition of the abbreviations and acronyms used in this data sheet can be found in Section 20.
