DS1339

· 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

· 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)

Voltage Range on Any Pin Relative to Ground..............................-0.3V to +6.0V
Operating Temperature Range.(Noncondensing)............................-40 to +85
Storage Temperature Range........................................-55 to +125
Soldering Temperature Range...See precautions in the Handling, PC Board Layout, and Assembly section.

Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those ndicated in the operational sections of the specifications is not implied. Exposure to the absolute maximum rating conditions for extended periods may affect device reliability.

The DS1339 serial real-time clock (RTC) is a lowpower clock/date device with two programmable timeof-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 months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with AM/PM indicator. The DS1339 has a built-in powersense circuit that detects power failures and automatically switches to the backup supply, maintaining time and date operation.