Description The M41T6x serial access TIMEKEEPER® is a low power serial RTC with a built-in 32.768 kHz oscillator. Eight registers are used for the clock/calendar function and are configured in binary coded decimal (BCD) format. An additional 8 registers provide status/control of alarm, 32 KHz output, calibration, and watchdog 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. Features ■ Serial RTC with alarm functions – 400 kHz I2C serial interface – Memory mapped registers for seconds, minutes, hours, day, date, month, year, and century – Tenths/hundredths of seconds register ■ 350 nA timekeeping current at 3 V ■ Timekeeping down to 1.0 V ■ 1.3 V to 4.4 V I2C bus operating voltage – 4.4 V max VCC suitable for lithium-ion battery operation ■ Low operating current of 35 µA (at 400 kHz) ■ 32 KHz square wave output is on at power-up. Suitable for driving a microcontroller in low-power mode. Can be disabled. (M41T62/63/64) ■ Programmable 1 Hz to 32 KHz square wave output (M41T62/63/64) ■ Programmable alarm with interrupt function (M41T62/65) ■ 32 KHz crystal oscillator integrates crystal load capacitors, works with high series resistance crystals ■ Oscillator stop detection monitors clock operation ■ Accurate programmable watchdog – 62.5 ms to 31 min timeout ■ Software clock calibration. Can adjust timekeeping to within ±2 parts per million (±5 seconds per month) ■ Automatic leap year compensation ■ –40 to +85 °C operation ■ Very small 3 mm x 3 mm, Lead-free 16-lead QFN
|