Real Time Clock Serial 16Byte 8-Pin CLCC T/R

The M41T6x is a low-power serial real-time clock (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 eight registers provide status/control of alarm, 32 KHz output, calibration, and watchdog functions. Addresses and data are transferred serially via a two-line, bidirectional 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 (M41T62/65), 32 KHz output (M41T62/63/64), programmable square wave output (M41T62/63/64), and watchdog output (M41T63/65). 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), 30- and 31-day months are made automatically.The M41T6x is supplied in two very small packages: a tiny, 3 mm x 3 mm 16-pin QFN which requires a user-supplied 32 KHz crystal, and an ultra-small 1.5 mm x 3.2 mm LCC with embedded crystal - no external crystal is required.

Serial real-time clock (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 V_CCsuitable 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

Two package options:

Very small 3 mm x 3 mm, lead-free & halogen-free (ECOPACK2® ) 16-lead QFN

Ultra-small 1.5 mm x 3.2 mm, lead-free & halogen-free (ECOPACK2® ) 8-pin ceramic leadless chip carrier with embedded 32 KHz crystal - no external oscillator components required (M41T62)