M41T81SMY6

Product Summary

The M41T81SMY6 is a Serial Access TIMEKEEPER SRAM. The M41T81SMY6 is a low power Serial RTC with a built-in 32.768kHz 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, bi-directional I2C interface. The built-in address register is incremented automatically after each WRITE or READ data byte. The M41T81SMY6 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 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.

Parametrics

M41T81SMY6 absolute maximum ratings: (1)TSTG Storage Temperature (VCC Off, Oscillator Off)SOIC: -55 to 125 ℃; (2)VCC Supply Voltage: -0.3 to 7 V; (3)TSLD Lead Solder Temperature for 10 Seconds Lead-free lead finish: 260 ℃, Standard (SnPb)lead finish: 240 ℃; (4)VIO Input or Output Voltages: -0.3 to Vcc+0.3 V; (5)IO Output Current: 20 mA; (6)PD Power Dissipation: 1 W.

Features

M41T81SMY6 features: (1)counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century; (2)32khz crystal oscillator with integrated load capacitance (12.5pf)which provides exceptional oscillator stability and high crystal series resistance operation); (3)oscillator stop detection (monitors clock operation); (4)serial interface supports i2c bus (400khz protocol); (5)ultra-low battery supply current of 0.6μa (typ); (6)2.0 to 5.5v clock operating voltage; (7)power-down time stamp (ht bit)which allows determination of time elapsed in battery back-up; (8)battery low flag; (9)programmable alarm and interrupt function (valid even during battery back-up mode); (10)accurate programmable watchdog timer (from 62.5ms to 128s); (11)software clock calibration (to compensate for crystal deviation due to temperature); (12)operating temperature of –40 to 85℃; (13)package options include an 8-lead soic or 18-lead embedded crystal soic.

Diagrams