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Low-Current, I2C, Serial Real-Time Clock for High-ESR Crystals

RTC Provides an Upgrade to the DS1339A by Supporting Crystals with a 100kΩ ESR

Product Details

Key Features

Applications/Uses

Simplified Block Diagram

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Key Features

  • Drop-In Replacement for DS1339
  • Supports High-ESR Crystals Up to 100kΩ to Allow Crystals to be Optimized for Cost and Space
  • 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 2200
    • Two Time-of-Day Alarms
    • Programmable Square-Wave Output Signal
  • Low-Power Operation Extends Battery Backup Run Time
    • Automatic Power-Fail Detect and Switch Circuitry
  • Simple Serial Port Interfaces to Most Microcontrollers
    • I2C Serial Interface
  • Underwriters Laboratories (UL®) Recognized

Applications/Uses

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

Description

The DS1339B serial real-time clock (RTC) is a 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 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 has a built-in power-sense circuit that detects power failures and automatically switches to the backup supply, maintaining time, date, and alarm operation.

Simplified Block Diagram

DS1339B: Functional Diagram DS1339B: Functional Diagram Zoom icon

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .