DS1339U-33+T&R

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, date, and alarm operation.

Applications

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

Key features

• Completely Manages All Timekeeping Functions
• Real-Time Clock Counts Seconds, Minutes, Hours, Date of the Month, Month, Day of the Week, and Year with Leap-Year Compensation Valid Up to 2100
• Two Time-of-Day Alarms
• Programmable Square-Wave Output
• Oscillator Stop Flag
• Interfaces to Most Microcontrollers
• I2C Serial Interface
• Low-Power Operation Extends Battery Backup Run Time
• Automatic Power-Fail Detect and Switch Circuitry
• Trickle-Charge Capability
• Underwriters Laboratories Recognized
• Surface-Mount Package with an Integrated Crystal (DS1339C Saves Additional Space and Simplifies Design)