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SPI Real-Time Clock/Calendar

PCF2123
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NXP’s Real-Time Clocks

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The PCF2123 is a CMOS Real-Time Clock (RTC) and calendar optimized for low power applications. Data is transferred serially via a Serial Peripheral Interface (SPI-bus) with a maximum data rate of 6.25 Mbit/s. An alarm and timer function is also available providing the possibility to generate a wake-up signal on an interrupt pin. An offset register allows fine tuning of the clock.

Block Diagram

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PCF2123

PCF2123 Block Diagram

PCF2123TS, PCF2123U

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Features

Key Features

  • Real time clock provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal
  • Low backup current while running: typical 100 nA at VDD = 2.0 V and Tamb = 25 ℃
  • Resolution: seconds to years
  • Watchdog functionality
  • Freely programmable timer and alarm with interrupt capability
  • Clock operating voltage: 1.1 V to 5.5 V
  • 3 line SPI-bus with separate, but combinable data input and output
  • Serial interface at VDD = 1.8 V to 5.5 V
  • 1 second or 1 minute interrupt output
  • Integrated oscillator load capacitors for CL = 7 pF
  • Internal Power-On Reset (POR)
  • Open-drain interrupt and clock output pins
  • Programmable offset register for frequency adjustment

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N true 0 PSPPCF2123en 12 Application Note Application Note t789 3 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 User Guide User Guide t792 2 en_US en_US en Data Sheet Data Sheet 1 1 6.0 English 1442056278115704925558 PSP 821.0 KB None None documents None 1442056278115704925558 /docs/en/data-sheet/PCF2123.pdf 821043 /docs/en/data-sheet/PCF2123.pdf PCF2123 documents N N 2013-07-15 SPI Real time clock/calendar /docs/en/data-sheet/PCF2123.pdf /docs/en/data-sheet/PCF2123.pdf Data Sheet N 980000996212993340 2023-08-24 pdf N en Jul 15, 2013 980000996212993340 Data Sheet Y N SPI Real time clock/calendar Application Note Application Note 3 2 1.0 English Improved timekeeping accuracy with PCF85063, PCF8523 and PCF2123 using an external temperature sensor 1442087074494735975495 PSP 316.8 KB None None documents None 1442087074494735975495 /docs/en/application-note/AN11247.pdf 316783 /docs/en/application-note/AN11247.pdf AN11247 documents N N 2015-03-06 Improved timekeeping accuracy with PCF85063, PCF8523 and PCF2123 using an external temperature sensor /docs/en/application-note/AN11247.pdf /docs/en/application-note/AN11247.pdf Application Note N 645036621402383989 2024-04-23 pdf N en Mar 6, 2015 645036621402383989 Application Note Y N Improved timekeeping accuracy with PCF85063, PCF8523 and PCF2123 using an external temperature sensor 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 4 2.0 English 1442087073862722241763 PSP 1.7 MB None None documents None 1442087073862722241763 /docs/en/application-note/AN10706.pdf 1672029 /docs/en/application-note/AN10706.pdf AN10706 documents N N 2016-07-11 Handling bare die /docs/en/application-note/AN10706.pdf /docs/en/application-note/AN10706.pdf Application Note N 645036621402383989 2024-07-12 pdf N en Jun 16, 2011 645036621402383989 Application Note Y N Handling bare die User Guide User Guide 2 5 1.0 English Demo Board OM13512 for the SPI-Bus RTC PCF2123 1442125672623684843491 PSP 400.7 KB None None documents None 1442125672623684843491 /docs/en/user-guide/UM10759.pdf 400713 /docs/en/user-guide/UM10759.pdf UM10759 documents N N 2015-10-05 Demo Board OM13512 for the SPI-Bus RTC PCF2123 /docs/en/user-guide/UM10759.pdf /docs/en/user-guide/UM10759.pdf User Guide N 132339537837198660 2024-04-23 pdf N en Oct 5, 2015 132339537837198660 User Guide Y N Demo Board OM13512 for the SPI-Bus RTC PCF2123 6 2.1 English 1442125649798715943478 PSP 983.6 KB None None documents None 1442125649798715943478 /docs/en/user-guide/UM10301.pdf 983634 /docs/en/user-guide/UM10301.pdf UM10301 documents N N 2016-07-11 User Manual for NXP Real Time Clocks PCF85x3, PCF85x63, PCA8565, PCF2123, and PCA21125 /docs/en/user-guide/UM10301.pdf /docs/en/user-guide/UM10301.pdf User Guide N 132339537837198660 2025-01-10 pdf N en Jul 24, 2015 132339537837198660 User Guide Y N User Manual for NXP Real Time Clocks PCF85x3, PCF85x63, PCA8565, PCF2123, and PCA21125 Brochure Brochure 1 7 1.0 English NXP provides broad portfolio of lower power Real Time Clocks 1442048649860716713778 PSP 289.3 KB None None documents None 1442048649860716713778 /docs/en/brochure/75017076.pdf 289342 /docs/en/brochure/75017076.pdf 75017076 documents N N 2019-08-21 NXP ultra-low-power RTC/calendars PCF8523 and PCF2123 /docs/en/brochure/75017076.pdf /docs/en/brochure/75017076.pdf Brochure N 712453003803778552 2022-12-07 pdf N en Aug 21, 2019 712453003803778552 Brochure Y N NXP ultra-low-power RTC/calendars PCF8523 and PCF2123 Package Information Package Information 2 8 2 English Plastic Thermal Enhanced Very Thin Quad Flat Package; No Leads; 16 Terminals; Body 3 x 3 x 0.85mm 1455079738102714704672 PSP 135.8 KB None None documents None 1455079738102714704672 /docs/en/package-information/SOT758-1.pdf 135802 /docs/en/package-information/SOT758-1.pdf SOT758-1 documents N N 2016-02-12 SOT758-1 /docs/en/package-information/SOT758-1.pdf /docs/en/package-information/SOT758-1.pdf Package Information N 302435339416912908 2024-06-18 pdf N en Jun 18, 2024 302435339416912908 Package Information Y N SOT758-1 9 1.0 English 1455079139512706823552 PSP 291.5 KB None None documents None 1455079139512706823552 /docs/en/package-information/SOT402-1.pdf 291544 /docs/en/package-information/SOT402-1.pdf SOT402-1 documents N N 2016-10-08 plastic thin shrink small outline package; 14 leads; body width 4.4 mm /docs/en/package-information/SOT402-1.pdf /docs/en/package-information/SOT402-1.pdf Package Information N 302435339416912908 2024-04-12 pdf N en Feb 8, 2016 302435339416912908 Package Information Y N plastic thin shrink small outline package; 14 leads; body width 4.4 mm Packing Information Packing Information 2 10 2.0 English HVQFN16; Reel Pack; SMD, 13"Q1/T1 Standard Product Orientation Orderable Part Number Ending ,118 or JOrdering Code (12NC) Ending 118 1442131584071694621487 PSP 267.8 KB None None documents None 1442131584071694621487 /docs/en/packing/SOT758-1_118.pdf 267807 /docs/en/packing/SOT758-1_118.pdf SOT758-1_118 documents N N 2013-04-18 HVQFN16; Reel Pack; SMD, 13"Q1/T1 Standard Product Orientation Orderable Part Number Ending ,118 or JOrdering Code (12NC) Ending 118 /docs/en/packing/SOT758-1_118.pdf /docs/en/packing/SOT758-1_118.pdf Packing Information N 145666923842250347 2024-04-23 pdf N en Apr 18, 2013 145666923842250347 Packing Information Y N HVQFN16; Reel Pack; SMD, 13"Q1/T1 Standard Product Orientation Orderable Part Number Ending ,118 or JOrdering Code (12NC) Ending 118 11 1.0 English TSSOP14; Reel pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,118 or JOrdering code (12NC) ending 118 1442131432535729363194 PSP 222.1 KB None None documents None 1442131432535729363194 /docs/en/packing/SOT402-1_118.pdf 222068 /docs/en/packing/SOT402-1_118.pdf SOT402-1_118 documents N N 2013-04-17 TSSOP14; Reel pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,118 or JOrdering code (12NC) ending 118 /docs/en/packing/SOT402-1_118.pdf /docs/en/packing/SOT402-1_118.pdf Packing Information N 145666923842250347 2024-04-23 pdf N en Apr 8, 2013 145666923842250347 Packing Information Y N TSSOP14; Reel pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,118 or JOrdering code (12NC) ending 118 Selector Guide Selector Guide 1 12 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 false 0 PCF2123 downloads en true 1 Y PSP Y Y Application Note 3 /docs/en/application-note/AN11247.pdf 2015-03-06 1442087074494735975495 PSP 2 Mar 6, 2015 Application Note Improved timekeeping accuracy with PCF85063, PCF8523 and PCF2123 using an external temperature sensor None /docs/en/application-note/AN11247.pdf English documents 316783 None 645036621402383989 2024-04-23 N /docs/en/application-note/AN11247.pdf Improved timekeeping accuracy with PCF85063, PCF8523 and PCF2123 using an external temperature sensor /docs/en/application-note/AN11247.pdf documents 645036621402383989 Application Note N en None Y pdf 1.0 N N Improved timekeeping accuracy with PCF85063, PCF8523 and PCF2123 using an external temperature sensor 316.8 KB AN11247 N 1442087074494735975495 /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 /docs/en/application-note/AN10706.pdf 2016-07-11 1442087073862722241763 PSP 4 Jun 16, 2011 Application Note None /docs/en/application-note/AN10706.pdf English documents 1672029 None 645036621402383989 2024-07-12 N /docs/en/application-note/AN10706.pdf Handling bare die /docs/en/application-note/AN10706.pdf documents 645036621402383989 Application Note N en None Y pdf 2.0 N N Handling bare die 1.7 MB AN10706 N 1442087073862722241763 Brochure 1 /docs/en/brochure/75017076.pdf 2019-08-21 1442048649860716713778 PSP 7 Aug 21, 2019 Brochure NXP provides broad portfolio of lower power Real Time Clocks None /docs/en/brochure/75017076.pdf English documents 289342 None 712453003803778552 2022-12-07 N /docs/en/brochure/75017076.pdf NXP ultra-low-power RTC/calendars PCF8523 and PCF2123 /docs/en/brochure/75017076.pdf documents 712453003803778552 Brochure N en None Y pdf 1.0 N N NXP ultra-low-power RTC/calendars PCF8523 and PCF2123 289.3 KB 75017076 N 1442048649860716713778 Data Sheet 1 /docs/en/data-sheet/PCF2123.pdf 2013-07-15 1442056278115704925558 PSP 1 Jul 15, 2013 Data Sheet None /docs/en/data-sheet/PCF2123.pdf English documents 821043 None 980000996212993340 2023-08-24 N /docs/en/data-sheet/PCF2123.pdf SPI Real time clock/calendar /docs/en/data-sheet/PCF2123.pdf documents 980000996212993340 Data Sheet N en None Y pdf 6.0 N N SPI Real time clock/calendar 821.0 KB PCF2123 N 1442056278115704925558 Package Information 2 /docs/en/package-information/SOT758-1.pdf 2016-02-12 1455079738102714704672 PSP 8 Jun 18, 2024 Package Information Plastic Thermal Enhanced Very Thin Quad Flat Package; No Leads; 16 Terminals; Body 3 x 3 x 0.85mm None /docs/en/package-information/SOT758-1.pdf English documents 135802 None 302435339416912908 2024-06-18 N /docs/en/package-information/SOT758-1.pdf SOT758-1 /docs/en/package-information/SOT758-1.pdf documents 302435339416912908 Package Information N en None Y pdf 2 N N SOT758-1 135.8 KB SOT758-1 N 1455079738102714704672 /docs/en/package-information/SOT402-1.pdf 2016-10-08 1455079139512706823552 PSP 9 Feb 8, 2016 Package Information None /docs/en/package-information/SOT402-1.pdf English documents 291544 None 302435339416912908 2024-04-12 N /docs/en/package-information/SOT402-1.pdf plastic thin shrink small outline package; 14 leads; body width 4.4 mm /docs/en/package-information/SOT402-1.pdf documents 302435339416912908 Package Information N en None Y pdf 1.0 N N plastic thin shrink small outline package; 14 leads; body width 4.4 mm 291.5 KB SOT402-1 N 1455079139512706823552 Packing Information 2 /docs/en/packing/SOT758-1_118.pdf 2013-04-18 1442131584071694621487 PSP 10 Apr 18, 2013 Packing Information HVQFN16; Reel Pack; SMD, 13"Q1/T1 Standard Product Orientation Orderable Part Number Ending ,118 or JOrdering Code (12NC) Ending 118 None /docs/en/packing/SOT758-1_118.pdf English documents 267807 None 145666923842250347 2024-04-23 N /docs/en/packing/SOT758-1_118.pdf HVQFN16; Reel Pack; SMD, 13"Q1/T1 Standard Product Orientation Orderable Part Number Ending ,118 or JOrdering Code (12NC) Ending 118 /docs/en/packing/SOT758-1_118.pdf documents 145666923842250347 Packing Information N en None Y pdf 2.0 N N HVQFN16; Reel Pack; SMD, 13"Q1/T1 Standard Product Orientation Orderable Part Number Ending ,118 or JOrdering Code (12NC) Ending 118 267.8 KB SOT758-1_118 N 1442131584071694621487 /docs/en/packing/SOT402-1_118.pdf 2013-04-17 1442131432535729363194 PSP 11 Apr 8, 2013 Packing Information TSSOP14; Reel pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,118 or JOrdering code (12NC) ending 118 None /docs/en/packing/SOT402-1_118.pdf English documents 222068 None 145666923842250347 2024-04-23 N /docs/en/packing/SOT402-1_118.pdf TSSOP14; Reel pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,118 or JOrdering code (12NC) ending 118 /docs/en/packing/SOT402-1_118.pdf documents 145666923842250347 Packing Information N en None Y pdf 1.0 N N TSSOP14; Reel pack; SMD, 13"Q1/T1 Standard product orientationOrderable part number ending ,118 or JOrdering code (12NC) ending 118 222.1 KB SOT402-1_118 N 1442131432535729363194 Selector Guide 1 /docs/en/product-selector-guide/RTCSelectorGuideA4.pdf 2020-01-21 1579625550018748134969 PSP 12 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 User Guide 2 /docs/en/user-guide/UM10759.pdf 2015-10-05 1442125672623684843491 PSP 5 Oct 5, 2015 User Guide Demo Board OM13512 for the SPI-Bus RTC PCF2123 None /docs/en/user-guide/UM10759.pdf English documents 400713 None 132339537837198660 2024-04-23 N /docs/en/user-guide/UM10759.pdf Demo Board OM13512 for the SPI-Bus RTC PCF2123 /docs/en/user-guide/UM10759.pdf documents 132339537837198660 User Guide N en None Y pdf 1.0 N N Demo Board OM13512 for the SPI-Bus RTC PCF2123 400.7 KB UM10759 N 1442125672623684843491 /docs/en/user-guide/UM10301.pdf 2016-07-11 1442125649798715943478 PSP 6 Jul 24, 2015 User Guide None /docs/en/user-guide/UM10301.pdf English documents 983634 None 132339537837198660 2025-01-10 N /docs/en/user-guide/UM10301.pdf User Manual for NXP Real Time Clocks PCF85x3, PCF85x63, PCA8565, PCF2123, and PCA21125 /docs/en/user-guide/UM10301.pdf documents 132339537837198660 User Guide N en None Y pdf 2.1 N N User Manual for NXP Real Time Clocks PCF85x3, PCF85x63, PCA8565, PCF2123, and PCA21125 983.6 KB UM10301 N 1442125649798715943478 true Y Products

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