1 General description
The PCF85263A is a CMOS 1 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-bus interface and
quartz crystal calibration.
For a selection of NXP Real-Time Clocks, see Table 71
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 999 999 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 μA 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
• Packages offered: SI8, TSSOP8, TSSOP10, HXSON10 and WLCSP12
3 Applications
• Printers and copiers
• Electronic metering
• Digital cameras
• White goods
• Elapsed time counter