DS1302 REAL-TIME CLOCK MODULE / WITH BATTERY CR2032 (2 pcs)

The DS1302 trickle-charge timekeeping chip contains a real-time clock/calendar and 31 bytes of static RAM. It communicates with a microprocessor via a simple serial interface. The real-time 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 an AM/PM indicator.
Features

manages all timekeeping functions: real-time clock counts seconds, minutes, hours, date of the month, month, day of the week, and year with leap year
31 x 8 battery-backed general-purpose RAM
simple serial port interfaces to most microcontrollers: simple 3-wire interface
TTL compatible: VCC = 5 V
single-byte or multiple-byte (burst mode) data transfer for read or write of clock or RAM data
low power operation extends battery backup run time: 2.0 V to 5.5 V full operation
uses less than 300 nA at 2.0 V
temperature range: 0°C to +70°C