DESCRIPTION
The DS1307 Serial Real-Time Clock is a low-power, full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV SRAM. Address and data are transferred serially via a 2-wire, bi-directional bus. 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 AM/PM indicator. The DS1307 has a built-in power sense circuit that detects power failures and automatically switches to the battery supply.

FEATURES
■ Real-time clock (RTC) counts seconds, minutes, hours, date of the month, month, day of the week, and year with leap-year compensation valid up to 2100
■ 56-byte, battery-backed, nonvolatile (NV) RAM for data storage
■ Two-wire serial interface
■ Programmable squarewave output signal
■ Automatic power-fail detect and switch circuitry
■ Consumes less than 500nA in battery backup mode with oscillator running
■ Optional industrial temperature range: -40°C to +85°C
■ Available in 8-pin DIP or SOIC
■ Underwriters Laboratory (UL) recognized