GENERAL DESCRIPTION
The DS1339serial real-time clock (RTC) isa low power clock/date device with two programmable time of-day alarms and a programmable square-wave output. Address and data are transferred serially through an I2C bus. The clock/date provides seconds, minutes, hours, day, date, month, and year information. The date at  the end of the month is automatically adjusted for month swith fewer than 31 days, including corrections for leapyear. The clock operates ineither the 24 our or 12 hour format with AM/PM indicator. The DS1339 has a built-in power sense  circuit that detects power  failures and automatically switchesto the backup supply, maintaining time, date, andalarm operation.

FEATURES
■ Real-Time Clock (RTC) Counts Seconds, Minutes, Hours, Day, Date, Month, and Year with Leap Year Compensation Valid Up to 2100
■ Available in a Surface-Mount Package with an Integrated Crystal (DS1339C)
■ I2C Serial Interface
■ Two Time-of-Day Alarms
■ Programmable Square-Wave Output
■ Oscillator Stop Flag
■ Automatic Power-Fail Detect and Switch Circuitry
■ Trickle-Charge Capability
■ Underwriters Laboratory (UL) Recognized

APPLICATIONS
    Handhelds (GPS, POS Terminals)
    Consumer Electronics (Set-Top Box, Digital Recording, Network Appliance)
    Office Equipment (Fax/Printers, Copier)
    Medical (Glucometer, Medicine Dispenser)
    Telecommunications (Routers, Switches, Servers)
    Other (Utility Meter, Vending Machine, Thermostat, Modem)