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DS1302 Timekeeping Chip

  • 604-00005: DS1302 Timekeeping Chip
  • 604-00005: DS1302 Timekeeping Chip Alternate View
In Stock: 19
Product ID 604-00005


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.

Only three wires are required to communicate with the clock/RAM: CE (chip enable), I/O (data line) and SCLK (serial clock). Data can be transferred to and from the clock/RAM 1 byte at a time, or in a burst of up to 31 bytes. The DS1302 is designed to operate on very low power, and retain the data and clock information on less than 1 µW.

Key Feautres:

  • Counts seconds, minutes, hours, date of the month, month, day of the week, and year
  • Leap-Year Compensation Valid Up to 2100
  • Supports 24 hour mode or 12 hour mode with AM/PM indicator
  • 31 byte of static RAM

Application Ideas:

  • Use with temperature sensor to create a custom digital thermostat
  • Custom clock
  • Project timer

Note: A 32.768 kHz Crystal (#251-03230) with a 6 pF load capacitance is needed (sold separately).


  • Voltage requirements: 2-5 VDC
  • Current requirements: <300nA
  • Communication: 3-wire synchronous serial (SPI)
  • Package: DIP-8 (.300")
  • Operating temp range: -32° to +185° F (-0° to + 70° C)


Downloads & Documentation

Download Details More Info
DS1302 BASIC Stamp Sample Code - 12.28 KB | updated: 04 Oct 2012 - 2:07 pm
DS1302 Datasheet - 110.27 KB | updated: 04 Oct 2012 - 2:09 pm

Additional Resources