PCF85263AX Datasheet PDF - NXP Semiconductors.

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

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

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