ST M41T81M6F

Часы/календарьСигнал тревоги, високосный год, выход квадратной волны, сторожевой таймер

Overview

The M41T81M6F is a low-power serial RTC with a built-in 32.768 kHz oscillator (external crystal controlled). Eight bytes of the SRAM are used for the clock/calendar function and are configured in binary-coded decimal (BCD) format. An additional 12 bytes of SRAM provide status/control of alarm, watchdog and square wave 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.

The M41T81M6F has a built-in power sense circuit which detects power failures and automatically switches to the battery supply when a power failure occurs. The energy needed to sustain the SRAM and clock operations can be supplied by a small lithium button supply when a power failure occurs. Functions available to the user include a non-volatile, time-of-day clock/calendar, alarm interrupts, watchdog timer 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 M41T81M6F is supplied in an 8-pin SOIC.

Features

For all new designs use M41T81S

Counters for tenths/hundredths of seconds, seconds, minutes, hours, days, dates, months, years, 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 

Applications

Automotive 

Advanced driver assistance systems (ADAS) 

Enterprise systems 

Datacenter & enterprise computing 

Personal electronics 

Home theater & entertainment