Low-Current I²C RTC with 56-Byte NV RAM

 The DS1308 serial real-time clock (RTC) is a low-power, full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV RAM.

Address and data are transferred serially through an I²C interface. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with an AM/PM indicator.

The DS1308 has a built-in power-sense circuit that detects power failures and automatically switches to the backup supply, maintaining time and date operation.