1. General description

The PCF85263A is a CMOS1 Real-Time Clock (RTC) and calendar optimized for low

power consumption and with automatic switching to battery on main power loss. The RTC

can also be configured as a stop-watch (elapsed time counter). Three time log registers

triggered from battery switch-over as well as input driven events. Featuring clock output

and two independent interrupt signals, two alarms, I2C interface and quartz crystal

calibration.

For a selection of NXP Real-Time Clocks, see Table 72 on page 90

2. Features and benefits

 UL Recognized Component (PCF85263ATL)

 Provides year, month, day, weekday, hours, minutes, seconds and 100th seconds

based on a 32.768 kHz quartz crystal

 Stop-watch mode for elapsed time counting. From 100th seconds to 999999 hours

 Two independent alarms

 Battery back-up circuit

 WatchDog timer

 Three timestamp registers

 Two independent interrupt generators plus predefined interrupts at every second,

minute, or hour

 Frequency adjustment via programmable offset register

 Clock operating voltage: 0.9 V to 5.5 V

 Low current; typical 0.28 A at VDD = 3.0 V and Tamb = 25 C

 400 kHz two-line I2C-bus interface (at VDD = 1.8 V to 5.5 V)

 Programmable clock output for peripheral devices (32.768 kHz, 16.384 kHz,

8.192 kHz, 4.096 kHz, 2.048 kHz, 1.024 kHz, and 1 Hz)

 Configurable oscillator circuit for a wide variety of quartzes: CL = 6 pF, CL = 7 pF, and

CL = 12.5 pF

3. Applications

 Printers and copiers

 Electronic metering

 Digital cameras

 White goods

 Elapsed time counter

 Network powered devices

 Battery backed up systems

 Data loggers

 Digital voice recorders

 Mobile equipment

 Accurate high duration timer