Microchip MCP7940N I2C Real Time Clock, SOIC 8, 1.8V-5.5V

The Microchip MCP7940N is a battery-backed I2C real-time clock and calendar with SRAM, designed for accurate timekeeping and data retention in a wide range of applications. It tracks hours, minutes, seconds, days, months, years, and day of the week, with dual programmable alarms that can be set on all counters up to and including months. The device supports I2C communication up to 400 kHz and features an open-drain multifunctional output that can be configured for alarm assertion, a selectable frequency square wave, or as a general-purpose output.

Key features include a 64-byte battery-backed SRAM, automatic switchover to a backup supply when main power is lost, and time logging on switchover to and from battery mode. On-chip digital trimming offers ±1 PPM resolution and a ±129 PPM range to compensate for crystal tolerance and temperature variations. The MCP7940N operates over a wide voltage range of 1.8V to 5.5V, with a low typical timekeeping current of 1.2 µA at 3.3V, making it suitable for power-sensitive designs. It comes in an 8-pin SOIC package with an industrial temperature range of -40°C to +85°C and is AEC-Q100 qualified for automotive applications.

Ideal for embedded systems, data loggers, and automotive electronics, this RTC ensures reliable time and date tracking as well as data retention even during power outages.