DS1337 Datasheet

• Completely Manages All Timekeeping Functions
  • Real-Time Clock (RTC) Counts Seconds, Minutes, Hours, Day, Date, Month, and Year with Leap-Year Compensation Valid Up to 2100
  • Two Time-of-Day Alarms
  • Programmable Square-Wave Output Defaults to 32kHz on Power-Up
  • Oscillator Stop Flag
• Interfaces with Most Microcontrollers
  • I²C Serial Interface
• Surface-Mount Package with an Integrated Crystal (DC1337C) Saves Additional Space and Simplifies Design
• -40°C to +85°C Industrial Temperature Range Supports Operation in a Wide Range of Applications

• Consumer Electronics (Set-Top Box, VCR/Digital Recording)
• Handhelds (GPS, POS Terminal, MP3 Player)
• Medical (Glucometer, Medicine Dispenser)
• Office Equipment (Fax/Printer, Copier)
• Other (Utility Meter, Vending Machine, Thermostat, Modem)
• Telecommunications (Router, Switcher, Server)

The DS1337 serial real-time clock is a low-power clock/calendar 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/calendar 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 device is fully accessible through the serial interface while V_CC is between 1.8V and 5.5V. I²C operation is not guaranteed below 1.8V. Timekeeping operation is maintained with V_CC as low as 1.3V.