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Accurate RTC with Battery Backup

PCF2129
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NXP’s Real-Time Clocks

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The PCF2129 is a CMOS Real Time Clock (RTC) and calendar with an integrated Temperature Compensated Crystal (Xtal) Oscillator (TCXO) and a 32.768 kHz quartz crystal optimized for very high accuracy and very low power consumption. The PCF2129 has a selectable I²C-bus or SPI-bus, a backup battery switch-over circuit, a programmable watchdog function, a timestamp function, and many other features.

Block Diagram

PCF2129

PCF2129 Block Diagram
Get diagram PDF

Features

Key Features

  • Operating temperature range from -40 °C to +85 °C
  • Temperature Compensated Crystal Oscillator (TCXO) with integrated capacitors
  • Typical accuracy:
    • PCF2129AT: ±3 ppm from -15 °C to +60 °C
    • PCF2129T: ±3 ppm from -30 °C to +80 °C
  • Integration of a 32.768 kHz quartz crystal and oscillator in the same package
  • Provides year, month, day, weekday, hours, minutes, seconds and leap year correction
  • Timestamp function:
    • with interrupt capability
    • detection of two different events on one multilevel input pin (for example, for tamper detection)
  • Two line bidirectional 400 kHz Fast-mode I²C-bus interface
  • 3 line SPI-bus with separate data input and output (maximum speed 6.5 Mbit/s)
  • Battery backup input pin and switch-over circuitry
  • Battery backed output voltage
  • Battery low detection function
  • Power-On Reset Override (PORO)
  • Oscillator stop detection function
  • Interrupt output (open-drain)
  • Programmable 1 second or 1 minute interrupt
  • Programmable watchdog timer with interrupt
  • Programmable alarm function with interrupt capability
  • Programmable square output
  • Clock operating voltage: 1.8 V to 4.2 V
  • Low supply current: typical 0.70 μA at VDD = 3.3 V

Buy/Parametrics

2 results

Include 0 NRND

Part

Show description

Order

CAD Model

resolution

Interface

VDD (interface)

watchdog timer

Programmable alarm

countdown timer

VDD (clock)

Special features

leap year tracking

IDD (nA)

temperature compensation

AEC-Q100 compliant

PCF2129AT
Data Sheet

Replacement part(s): PCF2131TF

1 sec to year

I2C, SPI

1.8 to 4.2

yes

yes

no

1.8 to 4.2

—

yes

700

yes

no

PCF2129T
Data Sheet

Replacement part(s): PCF2131TF

1 sec to year

I2C, SPI

1.8 to 4.2

yes

yes

no

1.8 to 4.2

wide temp range of compensation

yes

700

yes

no

N true 0 PSPPCF2129en 13 Application Note Application Note t789 2 Brochure Brochure t518 1 Data Sheet Data Sheet t520 1 Package Information Package Information t790 2 Packing Information Packing Information t935 2 Selector Guide Selector Guide t528 1 Supporting Information Supporting Information t531 3 User Guide User Guide t792 1 en_US en_US en Data Sheet Data Sheet 1 1 8 English 1442062670440718848867 PSP 1.3 MB None None documents None 1442062670440718848867 /docs/en/data-sheet/PCF2129.pdf 1296389 /docs/en/data-sheet/PCF2129.pdf PCF2129 documents N N 2022-07-19 Accurate RTC with integrated quartz crystal for industrial applications /docs/en/data-sheet/PCF2129.pdf /docs/en/data-sheet/PCF2129.pdf Data Sheet N 980000996212993340 2022-12-07 pdf N en Jul 18, 2022 980000996212993340 Data Sheet Y N Accurate RTC with integrated quartz crystal for industrial applications Application Note Application Note 2 2 3.1 English Application and soldering information for the PCA2129 and PCF2129 TCXO RTCs 1442087329601714086673 PSP 174.2 KB None None documents None 1442087329601714086673 /docs/en/application-note/AN11186.pdf 174209 /docs/en/application-note/AN11186.pdf AN11186 documents N N 2015-03-06 Application and soldering information for the PCA2129 and PCF2129 TCXO RTCs /docs/en/application-note/AN11186.pdf /docs/en/application-note/AN11186.pdf Application Note N 645036621402383989 2024-04-23 pdf N en Mar 6, 2015 645036621402383989 Application Note Y N Application and soldering information for the PCA2129 and PCF2129 TCXO RTCs 3 1.0 English 1442087330310721534478 PSP 763.2 KB None None documents None 1442087330310721534478 /docs/en/application-note/AN10853.pdf 763238 /docs/en/application-note/AN10853.pdf AN10853 documents N N 2016-07-11 ESD and EMC sensitivity of IC /docs/en/application-note/AN10853.pdf /docs/en/application-note/AN10853.pdf Application Note N 645036621402383989 2025-02-10 pdf N en Mar 14, 2013 645036621402383989 Application Note Y N ESD and EMC sensitivity of IC User Guide User Guide 1 4 2.0 English 1442125773445717058146 PSP 1.2 MB None None documents None 1442125773445717058146 /docs/en/user-guide/UM10762.pdf 1152000 /docs/en/user-guide/UM10762.pdf UM10762 documents N 2015-09-12 User manual for the accurate RTC demo board OM13513 containing PCF2127T and PCF2129AT /docs/en/user-guide/UM10762.pdf /docs/en/user-guide/UM10762.pdf User Guide N 132339537837198660 2022-12-07 pdf en Oct 5, 2015 132339537837198660 User Guide Y N User manual for the accurate RTC demo board OM13513 containing PCF2127T and PCF2129AT Brochure Brochure 1 5 1.0 English 1442048295291733198594 PSP 908.0 KB None None documents None 1442048295291733198594 /docs/en/brochure/75017568.pdf 908000 /docs/en/brochure/75017568.pdf 75017568 documents N 2015-09-12 NXP<sup>&#174;</sup> aRTCs PCF2127, PCA2129 and PCF2129: High-precision aRTCs with embedded quartz crystal /docs/en/brochure/75017568.pdf /docs/en/brochure/75017568.pdf Brochure N 712453003803778552 2022-12-07 pdf en Jun 18, 2014 712453003803778552 Brochure Y N NXP<sup>&#174;</sup> aRTCs PCF2127, PCA2129 and PCF2129: High-precision aRTCs with embedded quartz crystal Package Information Package Information 2 6 1.0 English 1455079006955710023723 PSP 324.4 KB None None documents None 1455079006955710023723 /docs/en/package-information/SOT162-1.pdf 324359 /docs/en/package-information/SOT162-1.pdf SOT162-1 documents N N 2016-02-12 plastic small outline package; 16 leads; body width 7.5 mm /docs/en/package-information/SOT162-1.pdf /docs/en/package-information/SOT162-1.pdf Package Information N 302435339416912908 2024-07-12 pdf N en Feb 8, 2016 302435339416912908 Package Information Y N plastic small outline package; 16 leads; body width 7.5 mm 7 1.0 English plastic small outline package; 20 leads; body width 7.5 mm 1455079171621724647129 PSP 343.2 KB None None documents None 1455079171621724647129 /docs/en/package-information/SOT163-1.pdf 343226 /docs/en/package-information/SOT163-1.pdf SOT163-1 documents N N 2016-02-12 plastic small outline package; 20 leads; body width 7.5 mm /docs/en/package-information/SOT163-1.pdf /docs/en/package-information/SOT163-1.pdf Package Information N 302435339416912908 2024-10-21 pdf N en Feb 8, 2016 302435339416912908 Package Information Y N plastic small outline package; 20 leads; body width 7.5 mm Packing Information Packing Information 2 8 1.0 English SO20; Reel dry pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,518 or YOrdering code (12NC) ending 518 1442131455509715811918 PSP 284.1 KB None None documents None 1442131455509715811918 /docs/en/packing/SOT163-1_518.pdf 284066 /docs/en/packing/SOT163-1_518.pdf SOT163-1_518 documents N N 2014-12-16 SO20; Reel dry pack; SMD, 13"Q1/T1 Standard product orientation orderable part number ending ,518 or ordering code (12NC) ending 518 /docs/en/packing/SOT163-1_518.pdf /docs/en/packing/SOT163-1_518.pdf Packing Information N 145666923842250347 2024-04-23 pdf N en Dec 16, 2014 145666923842250347 Packing Information Y N SO20; Reel dry pack; SMD, 13"Q1/T1 Standard product orientation orderable part number ending ,518 or ordering code (12NC) ending 518 9 1.0 English SO16; Reel dry pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,518 or YOrdering code (12NC) ending 518 1442131439318725846542 PSP 277.1 KB None None documents None 1442131439318725846542 /docs/en/packing/SOT162-1_518.pdf 277123 /docs/en/packing/SOT162-1_518.pdf SOT162-1_518 documents N N 2014-11-26 SO16; Reel dry pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,518 or YOrdering code (12NC) ending 518 /docs/en/packing/SOT162-1_518.pdf /docs/en/packing/SOT162-1_518.pdf Packing Information N 145666923842250347 2024-07-12 pdf N en Nov 25, 2014 145666923842250347 Packing Information Y N SO16; Reel dry pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,518 or YOrdering code (12NC) ending 518 Selector Guide Selector Guide 1 10 0 Japanese リアルタイム・クロックセレクターガイド。高精度な計時、長い電池寿命、過酷な環境でのアプリケーションに、NXPの豊富なRTCのポートフォリオからお選びください。 1579625550018748134969ja PSP 1.1 MB None None documents None 1579625550018748134969 /docs/ja/product-selector-guide/RTCSelectorGuideA4.pdf 1111554 /docs/ja/product-selector-guide/RTCSelectorGuideA4.pdf RTCSelectorGuideA4 documents N N 2020-01-21 Real Time Clocks Selector Guide Brochure /docs/ja/product-selector-guide/RTCSelectorGuideA4.pdf /docs/ja/product-selector-guide/RTCSelectorGuideA4.pdf Selector Guide N 553557935274807777 2024-04-12 ja Apr 5, 2023 553557935274807777 Selector Guide Y N リアルタイム・ クロック 5 English Real Time Clocks Selector Guide. For highly accurate time-keeping, long battery life, and rugged environment applications, choose from NXP's extensive portfolio of RTCs. 1579625550018748134969 PSP 1.1 MB None None documents None 1579625550018748134969 /docs/en/product-selector-guide/RTCSelectorGuideA4.pdf 1111554 /docs/en/product-selector-guide/RTCSelectorGuideA4.pdf RTCSelectorGuideA4 documents N N 2020-01-21 Real Time Clocks Selector Guide Brochure /docs/en/product-selector-guide/RTCSelectorGuideA4.pdf /docs/en/product-selector-guide/RTCSelectorGuideA4.pdf Selector Guide N 553557935274807777 2024-04-12 pdf N en Apr 17, 2023 553557935274807777 Selector Guide Y N Real Time Clocks Selector Guide Brochure Supporting Information Supporting Information 3 11 1.0 English Reflow Soldering temperature profile 1442122749741692602431 PSP 34.6 KB None None documents None 1442122749741692602431 /docs/en/supporting-information/Reflow_Soldering_Profile.pdf 34577 /docs/en/supporting-information/Reflow_Soldering_Profile.pdf REFLOW_SOLDERING_PROFILE documents N N 2016-10-08 Reflow Soldering Profile /docs/en/supporting-information/Reflow_Soldering_Profile.pdf /docs/en/supporting-information/Reflow_Soldering_Profile.pdf Supporting Information N 371282830530968666 2024-11-28 pdf N en Feb 17, 2014 371282830530968666 Supporting Information Y N Reflow Soldering Profile 12 1.0 English Footprint for Wave Soldering 1442126382106720903168 PSP 8.3 KB None None documents None 1442126382106720903168 /docs/en/supporting-information/SO-SOJ-WAVE.pdf 8260 /docs/en/supporting-information/SO-SOJ-WAVE.pdf SO-SOJ-WAVE documents N N 2013-07-15 Footprint for Wave Soldering /docs/en/supporting-information/SO-SOJ-WAVE.pdf /docs/en/supporting-information/SO-SOJ-WAVE.pdf Supporting Information N 371282830530968666 2024-10-21 pdf N en Oct 8, 2009 371282830530968666 Supporting Information Y N Footprint for Wave Soldering 13 1.0 English Footprint for reflow soldering 1442122730480711091281 PSP 8.8 KB None None documents None 1442122730480711091281 /docs/en/supporting-information/SO-SOJ-REFLOW.pdf 8792 /docs/en/supporting-information/SO-SOJ-REFLOW.pdf SO-SOJ-REFLOW documents N N 2013-07-15 Footprint for reflow soldering /docs/en/supporting-information/SO-SOJ-REFLOW.pdf /docs/en/supporting-information/SO-SOJ-REFLOW.pdf Supporting Information N 371282830530968666 2024-10-21 pdf N en Oct 8, 2009 371282830530968666 Supporting Information Y N Footprint for reflow soldering false 0 PCF2129 downloads en true 1 Y PSP Y Y Application Note 2 /docs/en/application-note/AN11186.pdf 2015-03-06 1442087329601714086673 PSP 2 Mar 6, 2015 Application Note Application and soldering information for the PCA2129 and PCF2129 TCXO RTCs None /docs/en/application-note/AN11186.pdf English documents 174209 None 645036621402383989 2024-04-23 N /docs/en/application-note/AN11186.pdf Application and soldering information for the PCA2129 and PCF2129 TCXO RTCs /docs/en/application-note/AN11186.pdf documents 645036621402383989 Application Note N en None Y pdf 3.1 N N Application and soldering information for the PCA2129 and PCF2129 TCXO RTCs 174.2 KB AN11186 N 1442087329601714086673 /docs/en/application-note/AN10853.pdf 2016-07-11 1442087330310721534478 PSP 3 Mar 14, 2013 Application Note None /docs/en/application-note/AN10853.pdf English documents 763238 None 645036621402383989 2025-02-10 N /docs/en/application-note/AN10853.pdf ESD and EMC sensitivity of IC /docs/en/application-note/AN10853.pdf documents 645036621402383989 Application Note N en None Y pdf 1.0 N N ESD and EMC sensitivity of IC 763.2 KB AN10853 N 1442087330310721534478 Brochure 1 /docs/en/brochure/75017568.pdf 2015-09-12 1442048295291733198594 PSP 5 Jun 18, 2014 Brochure None /docs/en/brochure/75017568.pdf English documents 908000 None 712453003803778552 2022-12-07 /docs/en/brochure/75017568.pdf NXP<sup>&#174;</sup> aRTCs PCF2127, PCA2129 and PCF2129: High-precision aRTCs with embedded quartz crystal /docs/en/brochure/75017568.pdf documents 712453003803778552 Brochure N en None Y pdf 1.0 N NXP<sup>&#174;</sup> aRTCs PCF2127, PCA2129 and PCF2129: High-precision aRTCs with embedded quartz crystal 908.0 KB 75017568 N 1442048295291733198594 Data Sheet 1 /docs/en/data-sheet/PCF2129.pdf 2022-07-19 1442062670440718848867 PSP 1 Jul 18, 2022 Data Sheet None /docs/en/data-sheet/PCF2129.pdf English documents 1296389 None 980000996212993340 2022-12-07 N /docs/en/data-sheet/PCF2129.pdf Accurate RTC with integrated quartz crystal for industrial applications /docs/en/data-sheet/PCF2129.pdf documents 980000996212993340 Data Sheet N en None Y pdf 8 N N Accurate RTC with integrated quartz crystal for industrial applications 1.3 MB PCF2129 N 1442062670440718848867 Package Information 2 /docs/en/package-information/SOT162-1.pdf 2016-02-12 1455079006955710023723 PSP 6 Feb 8, 2016 Package Information None /docs/en/package-information/SOT162-1.pdf English documents 324359 None 302435339416912908 2024-07-12 N /docs/en/package-information/SOT162-1.pdf plastic small outline package; 16 leads; body width 7.5 mm /docs/en/package-information/SOT162-1.pdf documents 302435339416912908 Package Information N en None Y pdf 1.0 N N plastic small outline package; 16 leads; body width 7.5 mm 324.4 KB SOT162-1 N 1455079006955710023723 /docs/en/package-information/SOT163-1.pdf 2016-02-12 1455079171621724647129 PSP 7 Feb 8, 2016 Package Information plastic small outline package; 20 leads; body width 7.5 mm None /docs/en/package-information/SOT163-1.pdf English documents 343226 None 302435339416912908 2024-10-21 N /docs/en/package-information/SOT163-1.pdf plastic small outline package; 20 leads; body width 7.5 mm /docs/en/package-information/SOT163-1.pdf documents 302435339416912908 Package Information N en None Y pdf 1.0 N N plastic small outline package; 20 leads; body width 7.5 mm 343.2 KB SOT163-1 N 1455079171621724647129 Packing Information 2 /docs/en/packing/SOT163-1_518.pdf 2014-12-16 1442131455509715811918 PSP 8 Dec 16, 2014 Packing Information SO20; Reel dry pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,518 or YOrdering code (12NC) ending 518 None /docs/en/packing/SOT163-1_518.pdf English documents 284066 None 145666923842250347 2024-04-23 N /docs/en/packing/SOT163-1_518.pdf SO20; Reel dry pack; SMD, 13"Q1/T1 Standard product orientation orderable part number ending ,518 or ordering code (12NC) ending 518 /docs/en/packing/SOT163-1_518.pdf documents 145666923842250347 Packing Information N en None Y pdf 1.0 N N SO20; Reel dry pack; SMD, 13"Q1/T1 Standard product orientation orderable part number ending ,518 or ordering code (12NC) ending 518 284.1 KB SOT163-1_518 N 1442131455509715811918 /docs/en/packing/SOT162-1_518.pdf 2014-11-26 1442131439318725846542 PSP 9 Nov 25, 2014 Packing Information SO16; Reel dry pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,518 or YOrdering code (12NC) ending 518 None /docs/en/packing/SOT162-1_518.pdf English documents 277123 None 145666923842250347 2024-07-12 N /docs/en/packing/SOT162-1_518.pdf SO16; Reel dry pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,518 or YOrdering code (12NC) ending 518 /docs/en/packing/SOT162-1_518.pdf documents 145666923842250347 Packing Information N en None Y pdf 1.0 N N SO16; Reel dry pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,518 or YOrdering code (12NC) ending 518 277.1 KB SOT162-1_518 N 1442131439318725846542 Selector Guide 1 /docs/en/product-selector-guide/RTCSelectorGuideA4.pdf 2020-01-21 1579625550018748134969 PSP 10 Apr 17, 2023 Selector Guide Real Time Clocks Selector Guide. For highly accurate time-keeping, long battery life, and rugged environment applications, choose from NXP's extensive portfolio of RTCs. None /docs/en/product-selector-guide/RTCSelectorGuideA4.pdf English documents 1111554 None 553557935274807777 2024-04-12 N /docs/en/product-selector-guide/RTCSelectorGuideA4.pdf Real Time Clocks Selector Guide Brochure /docs/en/product-selector-guide/RTCSelectorGuideA4.pdf documents 553557935274807777 Selector Guide N en None Y pdf 5 N N Real Time Clocks Selector Guide Brochure 1.1 MB RTCSelectorGuideA4 N 1579625550018748134969 Supporting Information 3 /docs/en/supporting-information/Reflow_Soldering_Profile.pdf 2016-10-08 1442122749741692602431 PSP 11 Feb 17, 2014 Supporting Information Reflow Soldering temperature profile None /docs/en/supporting-information/Reflow_Soldering_Profile.pdf English documents 34577 None 371282830530968666 2024-11-28 N /docs/en/supporting-information/Reflow_Soldering_Profile.pdf Reflow Soldering Profile /docs/en/supporting-information/Reflow_Soldering_Profile.pdf documents 371282830530968666 Supporting Information N en None Y pdf 1.0 N N Reflow Soldering Profile 34.6 KB REFLOW_SOLDERING_PROFILE N 1442122749741692602431 /docs/en/supporting-information/SO-SOJ-WAVE.pdf 2013-07-15 1442126382106720903168 PSP 12 Oct 8, 2009 Supporting Information Footprint for Wave Soldering None /docs/en/supporting-information/SO-SOJ-WAVE.pdf English documents 8260 None 371282830530968666 2024-10-21 N /docs/en/supporting-information/SO-SOJ-WAVE.pdf Footprint for Wave Soldering /docs/en/supporting-information/SO-SOJ-WAVE.pdf documents 371282830530968666 Supporting Information N en None Y pdf 1.0 N N Footprint for Wave Soldering 8.3 KB SO-SOJ-WAVE N 1442126382106720903168 /docs/en/supporting-information/SO-SOJ-REFLOW.pdf 2013-07-15 1442122730480711091281 PSP 13 Oct 8, 2009 Supporting Information Footprint for reflow soldering None /docs/en/supporting-information/SO-SOJ-REFLOW.pdf English documents 8792 None 371282830530968666 2024-10-21 N /docs/en/supporting-information/SO-SOJ-REFLOW.pdf Footprint for reflow soldering /docs/en/supporting-information/SO-SOJ-REFLOW.pdf documents 371282830530968666 Supporting Information N en None Y pdf 1.0 N N Footprint for reflow soldering 8.8 KB SO-SOJ-REFLOW N 1442122730480711091281 User Guide 1 /docs/en/user-guide/UM10762.pdf 2015-09-12 1442125773445717058146 PSP 4 Oct 5, 2015 User Guide None /docs/en/user-guide/UM10762.pdf English documents 1152000 None 132339537837198660 2022-12-07 /docs/en/user-guide/UM10762.pdf User manual for the accurate RTC demo board OM13513 containing PCF2127T and PCF2129AT /docs/en/user-guide/UM10762.pdf documents 132339537837198660 User Guide N en None Y pdf 2.0 N User manual for the accurate RTC demo board OM13513 containing PCF2127T and PCF2129AT 1.2 MB UM10762 N 1442125773445717058146 true Y Products

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