The M41T8x are low-power serial I2C real-time clocks (RTCs) with a built-in 32.768 kHz oscillator (external crystal-controlled for the QFN16 and SO8 packages, embedded crystal for the SOX18 package). Eight bytes of the register map (see Table 2 on page 23) are used for the clock/calendar function and are configured in binary-coded decimal (BCD) format. An additional 17 bytes of the register map provide status/control of the two alarms, watchdog, 8-bit counter, and square wave functions. An additional seven bytes are made available as user SRAM. 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 M41T8x 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 battery when a power failure occurs. Functions available to the user include a non-volatile, time-of-day clock/calendar, two alarm interrupts, watchdog timer, programmable 8-bit counter, and square wave outputs. 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 M41T83 is supplied in either a QFN16 or an SOX18, 300 mil SOIC which includes an embedded 32 KHz crystal. The SOX18 package requires only a user-supplied battery to provide non-volatile operation. The M41T82 is available only in an SO8 package. https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2020-06-04 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2021-04-04 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2021-04-17 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2021-05-22 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2021-07-14 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2021-12-05 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2022-04-08 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2022-06-14 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2022-06-22 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2023-03-24 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2023-12-02 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2024-01-31 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2024-04-30 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2024-10-22 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2024-11-18 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2024-11-27 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2025-01-02 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2025-01-11 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2025-01-20 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2025-03-26 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2025-04-04 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2025-07-01 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2025-07-11 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2026-01-28 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2026-03-16 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2026-05-02 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2026-05-21 https://elecena.pl/product/16941412/m41t82sm6f-serial-i-c-bus-real-time-clock-rtc-with-battery-switchover 2026-07-08