串行访问实时时钟与闹钟 Serial Access Real-Time Clock with Alarms
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 VCCsuitable 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 lowpower 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 adjus 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