
STMicroelectronics
Description
The M41T00 is a low power serial real time clock with a built-in 32.768 kHz oscillator (external crystal controlled). 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.
Features
■ For new designs use M41T00S
■ Counters for seconds, minutes, hours, day, month, 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 (100 kHz protocol)
■ Ultra low battery supply current of 0.8 µA (typ at 3 V)
■ 2.0 to 5.5 V clock operating voltage
■ Automatic switchover and deselect circuitry
(for 3 V application select M41T00S datasheet)
■ Software clock calibration to compensate crystal deviation due to temperature
■ Automatic leap year compensation
■ Operating temperature of -40 to 85 °C