PCF8523TS/1,118 (NXP)

The PCF8523TS/1,118 is a CMOS Real-time Clock (RTC) and Calendar optimized for low power consumption. It provides year, month, day, weekday, hours, minutes and seconds based on a 32.768kHz quartz crystal. Data is transferred serially via the I?C-bus with a maximum data rate of 1000kbps. Alarm and timer functions are available with the possibility to generate a wake-up signal on an interrupt pin. An offset register allows fine-tuning of the clock. The PCF8523 has a backup battery switch-over circuit, which detects power failures and automatically switches to the battery supply when a power failure occurs.