The M41T81M6F is a low-power serial RTC with a built-in 32.768 kHz oscillator (external crystal controlled). Eight 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 I2C interface. The built-in address register is incremented automatically after each WRITE or READ data byte.

For all new designs use M41T81S

Counters for tenths/hundredths of seconds, seconds, minutes, hours, days, dates, months, years, and century

32 KHz crystal oscillator integrating load capacitance (12.5 pF) providing exceptional oscillator stability and high crystal series resistance operation

Serial interface supports I2C bus (400 kHz protocol)

Ultra-low battery supply current of 0.6 ΜA(typ at 3 V)

2.0 to 5.5 V clock operating voltage

Automatic switchover and deselect circuitry 

Automotive 

Advanced driver assistance systems (ADAS) 

Enterprise systems 

Datacenter & enterprise computing 

Personal electronics 

Home theater & entertainment