DESCRIPTION

The DS1307 Serial Real Time Clock is a low power, full BCD clock/calendar plus 56 bytes of nonvolatile 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 less 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 which detects power failures and automatically switches to the battery supply.

FEATURES

■ Real time clock 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 nonvolatile RAM for data storage

■ 2-wire serial interface

■ Programmable squarewave output signal

■ Automatic power-fail detect and switch circuitry

■ Consumes less than 500 nA in battery backup mode with oscillator running

■ Optional industrial temperature range

-40°C to +85°C (IND) available for DS1307 and DS1308

■ DS1307 available in 8-pin DIP or SOIC

■ DS1308 available in 36-pin SMD BGA (Ball Grid Array)

■ DS1308 accuracy is better than ±2 minute/month at 25°C

■ Recognized by Underwriters Laboratory