DS1339U-33+ (MAXIM INTEGRATED PRODUCTS)

The DS1339U-33+ is a serial Real-time Clock (RTC) with two programmable time-of-day alarms and a programmable square-wave output. Address and data are transferred serially through an I?C bus. The clock/date provides seconds, minutes, hours, day, date, month and year information. The date at the end of the month 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 AM/PM indicator. This has a built-in power-sense circuit that detects power failures and automatically switches to the backup supply, maintaining time, date and alarm operation.