GENERAL DESCRIPTION
The DS1307 serial real-time clock (RTC) is a lowpower,
full binary-coded decimal (BCD) clock/calendar
plus 56 bytes of NV SRAM. Address and data are
transferred serially through an I2C, bidirectional 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 backup supply.
Timekeeping operation continues while the part
operates from the backup 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, General-Purpose RAM
with Unlimited Writes
I2C Serial Interface
Programmable Square-Wave 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 Plastic DIP or SO
Underwriters Laboratories (UL) Recognized