M41T81SM6F

IC, RTC, I2C, W/ ALARM, 8-SO.

The M41T81SM6F is a low-power serial Real-time Clock (RTC) IC with a built-in 32.768kHz oscillator (external crystal controlled). 8 bytes of the SRAM are used for the clock/calendar function and are configured in binary-coded decimal (BCD) format. An additional 12 bytes of SRAM provide status/control of alarm, watchdog and square wave functions. Addresses and data are transferred serially via a two line, bidirectional I?C interface. The built-in address register is incremented automatically after each WRITE or READ data byte. It has a built-in power sense circuit which detects power failures and automatically switches to the battery supply when a power failure occurs. The energy needed to sustain the clock operations can be supplied by a small lithium button supply when a power failure occurs. Functions available to the user include a non-volatile, time-of-day clock/calendar, alarm interrupts, watchdog timer and programmable square wave output.