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Low power consumption and I2C RTC

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The PT7C4339 real-time clock is a low-power clock/calendar 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/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 PT7C4339 has a build-in power-sense circuit that detects power failures and automatically switch to the backup supply, maintaining time, date, and alarm operation.


  • Real-Time Clock (RTC) Including Time (Seconds, Minutes and Hours) and Calendar (Day, Date, Month and Year with Leap-Year Compensation Valid Up to 2100) counter functions (BCD code)
  • Available in a Surface-Mount Package with an Integrated Crystal (Only for PT7C4339C)
  • I2C Serial Interface supports I2C-Bus's high speed mode (400 kHz)
  • Programmable square wave output signal, defaults to 32 kHz on Power-up
  • Two Time-of-Day Alarms
  • Oscillator Stop Flag
  • Automatic Power-Fail Detect and Switch Circuitry
  • Temperature Range: -40°C to +85°C
  • Package: MSOP-8L and SOIC-8L for PT7C4339
  • TDFN4x4-8L for PT7C4339C

Product Specifications

Product Parameters

Compliance(Only Automotive supports PPAP) Standard
Time Display 12, 24
Interface I2C
Alarm Interrupt 1
Battery Backup 1
Clock Calibration 0

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Technical Documents

Recommended Soldering Techniques


Additional Technical Documents are available upon request:
Application information, Evaluation board, and Other technical documents

Request Documents
Orderable Part Number Status Package Environmental Compliance Packing Buy from Distributor /
Contact Sales
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Qty. Carrier
PT7C4339UEX Active MSOP-8 TPGP 2500 T&R Contact Sales Request Sample
PT7C4339WEX Active SO-8 TPGP 2500 T&R


Authorized Distributor Quantity Inventory Date Countries/Regions Buy Online
Digi-Key Electronics 7500 1/19/2022 Europe, Asia, North America Buy Now
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Environmental Compliance Legend:
LFF: Pb-Free Finish and RoHS 5/6
TLFP: Totally Pb-Free Product and RoHS 6/6
LFGP: Pb-free Finish and Green Product, RoHS 5/6 and Halogen Free
TPGP: Totally Pb-Free and Green Product, RoHS 6/6 and Halogen Free
GREEN: Halogen-free and RoHS compliant
RoHS: RoHS compliant but NOT halogen-free


Product Change Notices

PCN # Issue Date Implementation Date Subject
PCN-2510 2021-02-26 2021-05-26 Qualified Additional A/T Sites, Fab Site and Data Sheet Change
PCN-2493 2020-12-28 2021-03-28 Qualified Additional A/T Sites and Bill of Materials (BOM)
PCN-2448 2020-02-05 2020-08-05 Device End of Life (EOL)


Related Application FAQs