The MCP7940M-I/ST is an I²C™ Real-time Clock/Calendar (RTCC) tracks time using internal counters for hours, minutes, seconds, days, months, years and day of week. Alarms can be configured on all counters up to and including months. For usage and configuration, the MCP7940M supports I²C communications up to 400kHz. The open-drain, multi-functional output can be configured to assert on an alarm match, to output a selectable frequency square wave or as a general purpose output. The MCP7940M is designed to operate using a 32.768kHz tuning fork crystal with external crystal load capacitors. On-chip digital trimming can be used to adjust for frequency variance caused by crystal tolerance and temperature.
On-chip digital trimming/calibration – ±1PPM resolution, ±129PPM range
Dual programmable alarms
Versatile output pin – Clock output with selectable frequency
1.2μA at 3.3V Operating from VCC, low typical timekeeping current