Description

    The AT8310 is a low-power serial real-time clock (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. 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 AT8310 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. The eight clock address locations contain the century, year, month, date, day, hour, minute, and 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 AT8310 is supplied in an 8-pin SOIC.

 Features

    2.0 to 5.5 V clock operating voltage

    Counters for seconds, minutes, hours, day, date, month, year, and century

    Software clock calibration

    Automatic switchover and deselect circuitry (fixed reference)

     – V_CC = 2.7 to 5.5 V 2.5 V ≤ V_PDF ≤ 2.7 V

    Serial interface supports I²C-bus (400 kHz protocol)

    Low operating current of 300 µA

    Oscillator stop detection

    Battery or SuperCap^TM backup

    Operating temperature of –40 to 85 °C

    Ultra-low battery supply current of 0.6 µA

Logic diagram