M41T56M6F Datasheet PDF - ST Microelectronics

The M41T56M6F is a low-power, serial Real-time Clock (RTC) IC with 56 bytes of NVRAM. A built-in 32768Hz oscillator (external crystal controlled) and the first 8 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 2-line, bidirectional bus. The built-in address register is incremented automatically after each WRITE or READ data byte. The clock has a built-in power sense circuit which detects power failures and automatically switches to the battery supply during power failures. The energy needed to sustain the RAM and clock operations can be supplied from a small lithium coin cell.

● Counters for seconds, minutes, hours, day, date, month, years and century

● Serial interface supports I²C bus (100kHz protocol)

● Ultralow battery supply current of 450nA (typical at 3V)

● 5V ±10% Supply voltage

● Timekeeping down to 2.5V

● Automatic power-fail detect and switch circuitry

● 56-byte General purpose RAM

● Software clock calibration to compensate crystal deviation due to temperature

● Automatic leap year compensation