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. https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2020-06-13 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2021-04-04 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2021-04-17 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2021-07-14 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2021-07-22 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2021-08-08 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2021-12-06 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2022-04-08 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2022-06-14 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2022-06-22 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2023-10-12 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2023-12-10 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2024-04-04 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2024-11-18 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2025-01-20 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2025-03-26 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2025-04-04 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2025-06-13 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2025-07-11 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2025-10-18 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2025-12-22 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2026-01-28 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2026-02-06 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2026-05-21 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2026-07-08 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2026-07-27 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2026-08-16 https://elecena.pl/product/16968703/m41t81m6f-serial-real-time-clock-rtc-with-alarm 2026-08-26