DS1339B: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

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.

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
DS1339B: Functional Diagram
DS1339B: Functional Diagram
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)
DataSheet
titleDownload file
DS1339B Data SheetDS1339B.pdf
Parametrics
Part NumberInterfaceVSUPPLY
(V)
Time Keeping Current
(nA)
CL
(pF)
Memory TypeTime of Day AlarmsFunctionsPackage/PinsBudgetary
Price
typSee Notes
DS1339BI2C1.8 to 5.53006None2RTCµMAX/8$1.67 @1k
Related Products
  • DS1339A:Low-Current, I²C, Serial Real-Time Clock
  • DS1339:I²C Serial Real-Time Clock
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
DS1339BU+ActiveµMAX,;8 pin;15.6 mm²-40°C to +85°CLead Free
DS1339BU+TActiveµMAX,;8 pin;15.6 mm²-40°C to +85°CLead Free
DS1339B.pdf DS1339B
DS1339B_cn.pdf DS1339B
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Selecting a Backup Source for Real-Time Clocks DS3234
Lithium Coin-Cell Batteries: Predicting an Application Lifetime DS9034PCX
Design Considerations for Maxim Real-Time Clocks DS3234
Interfacing the DS1307 with an 8051-Compatible Microcontroller DS1340C
Using the Dallas Tricklecharge Timekeeper DS1672
Crystal Considerations with Maxim Real-Time Clocks (RTCs) DS3234
DS1339B_cn.pdf DS1339B