The OM13516UL is the evaluation board for PCF85263B. The NXP® PCF85263 is a CMOS real-time clock (RTC) and calendar, optimized for low-power consumption, that switches automatically to battery power when main power is lost. The PCF85263 can be configured as a stopwatch (or elapsed-time counter) with a resolution of up to 1/100 s. Three-time stamps make it easy to register special events, and the device can also register tamper detection or time of battery switchover.