The M41T81 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 M41T81 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 M41T81 is supplied in an 8-pin SOIC.
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|Part Number||Package||Packing Type||Operating Temperature (°C) (min)||Operating Temperature (°C) (max)||Marketing Status||Unit Price (US$) *||Quantity||NVRAM size (B)||ECCN (EU)||ECCN (US)||Country of Origin||More info||Order from ST||Order from Distributors|
|M41T81M6F||SO-8||Tape And Reel||-40||85||Active : Product is in volume production||1.106||1000||-||NEC||EAR99||-||MORE INFO||DISTRIBUTOR AVAILABILITY|
|Part Number||Marketing Status||Package||Grade||RoHS Compliance Grade||Material Declaration**|
(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.