The M41T80 is a low power serial RTC with a built-in 32.768 kHz oscillator (external crystal controlled). Eight registers are used for the clock/calendar function and are configured in binary coded decimal (BCD) format. An additional 12 registers provide status/control of alarm, 32 KHz output, and square wave functions. Addresses and data are transferred serially via a two line, bi-directional I2C interface. The built-in address register is incremented automatically after each WRITE or READ data byte.
Functions available to the user include a time-of-day clock/calendar, alarm interrupts, 32 KHz output, and programmable square wave output. The eight clock address locations contain the century, year, month, date, day, hour, minute, second and tenths/hundredths of a second in 24-hour BCD format. Corrections for 28, 29 (leap year - valid until year 2100), 30 and 31 day months are made automatically.
The M41T80 is supplied in an 8-pin SOIC.
- 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)
- 2.0 to 5.5 V clock operating voltage
- 32 KHz square wave on power-up to drive a microcontroller in low-power mode
- Programmable (1 Hz to 32 KHz) square wave
- Programmable alarm and interrupt function
- Low operating current of 200 μA
- Operating temperature of –40 to 85 °C
- ECOPACK®package available
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