STMICROELECTRONICS M41T01M6F

M41T01M6F is a low-power serial real-time clock (RTC) with built-in battery switchover circuit. This built-in 32.768kHz oscillator circuit works with an external crystal and does not need any load capacitors. The clock has a built-in power sense circuit which detects power failures and automatically switches to the battery supply during power failures. Eight bytes of the RAM are used for the clock/calendar function and are configured in binary-coded decimal (BCD) format. Addresses and data are transferred serially via a two-line bidirectional bus. The built-in address register is incremented automatically after each WRITE or READ data byte. The energy needed to sustain the RAM and clock operations can be supplied from a small lithium coin cell.