The DS1307ZN+T&R from Maxim Integrated Products is a 64 x 8, serial, I2C real-time clock in 8 pin SOIC package. The serial real-time clock (RTC) is a low-power, 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.
RTC counts seconds, minutes, hours, date of the month, month, day of the week, year with leap-year
Compensation valid up to 2100
56byte, battery backed, general purpose RAM with unlimited writes
Programmable square wave output signal
Simple serial port interfaces to most microcontrollers I2C serial interface
Low power operation extends battery backup run time
Consumes less than 500nA in battery-backup mode with oscillator running