Real-time clock IC is accurate and low cost

The low-cost MCP7940M real-time clock/calendar IC includes a digital-trimming circuit that can compensate up to ±127 ppm for crystal error. The device is available in 8-pin MSOP, PDIP, SOIC, TSSOP, and 2 x 3 mm TDFN packages and comes with a 64-bit unique ID.

The chip has 64 bytes of SRAM, operates over -40 to 85C, and uses an I2C interface. Standby current is 1 µa maximum at 1.8 to 5.5 v and dynamic current in read mode is 400 µa max. (From $0.45 ea/10,000 available now.)

by Jim Harrison

Microchip Technology , Chandler , AZ
Sales 480-792-7200
www.microchip.com