MCP7940N-I/ST Datasheet PDF - Microchip

The MCP7940N-I/ST is a low-power Real-Time Clock (RTC) uses digital timing compensation for an accurate clock/calendar, a programmable output control for versatility, a power sense circuit that automatically switches to the backup supply. Using a 32.768kHz crystal, it tracks time using several internal registers. For communication, the MCP7940N uses the I²C™ bus. The clock/calendar automatically adjusts for months with fewer than 31 days, including corrections for leap years. The clock operates in either the 24-hour or 12-hour format with an AM/PM indicator and settable alarm(s) to the second, minute, hour, day of the week, date or month. Using the programmable CLKOUT, frequencies of 32.768, 8.192 and 4.096kHz and 1Hz can be generated from the external crystal.

● On-chip digital trimming/calibration

● Programmable open-drain output control

● 64-byte SRAM, battery backed

● Automatic VCC switchover to VBAT backup supply

● Power-fail time-stamp for battery switchover

● Low-power CMOS technology

● >4000V ESD protection