Features

 For all new designs use M41T81S

 Counters for tenths/hundredths of seconds,

seconds, minutes, hours, day, date, month,

year, 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 (for

3 V application select M41T81S datasheet)

 Power-down time stamp (HT bit) allowing

determination of time elapsed in battery

backup

 Programmable alarm and interrupt function

(valid even during battery backup mode)

 Accurate programmable watchdog timer (from

62.5 ms to 128 s)

 Software clock calibration to compensate

crystal deviation due to temperature

 Operating temperature of –40 to 85 °C

 ECOPACK® package available