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PCF2129T

Real Time Clock (RTC)

The PCF2129T is a real time clock (rtc) from NXP Semiconductors. View the full PCF2129T datasheet below including key specifications.

PCF2129T shares its datasheet with PCF2129T/2,518, whose page lists every part number it covers.

Official PCF2129T datasheet (PDF) — the source this page was extracted from.

Manufacturer

NXP Semiconductors

Package

SO16

PCF2129T Key Specifications

ParameterValue
Current - Timekeeping (Max)1.5µA @ 3.3V
Date FormatYY-MM-DD-dd
DigiKey ProgrammableNot Verified
FeaturesAlarm, Leap Year, Square Wave Output, TCXO/Crystal, Watchdog Timer
InterfaceI2C, 2-Wire Serial
Mounting TypeSurface Mount
Operating Temperature-40°C ~ 85°C
Package / Case16-SOIC (0.295", 7.50mm Width)
Supplier Device Package16-SO
Time FormatHH:MM:SS (12/24 hr)
TypeClock/Calendar
Supply Voltage1.8V ~ 4.2V
Voltage - Supply, Battery1.8V ~ 4.2V

PCF2129T Overview

Part: PCF2129T/2,518 (PCF2129 family) — NXP Semiconductors

Type: Temperature-Compensated Real-Time Clock/Calendar (TCXO RTC) with integrated 32.768 kHz quartz crystal

Description: Accurate RTC/calendar with integrated TCXO and quartz crystal, ±3 ppm typical accuracy, 1.8–4.2 V clock operating voltage, I²C (400 kHz) or SPI (6.5 Mbit/s) interface, and 0.70 μA typical supply current at VDD = 3.3 V.

Operating Conditions:

  • Clock operating voltage: 1.8 V to 4.2 V
  • Operating temperature: -40 to +85 °C
  • I²C-bus: 400 kHz Fast-mode; SPI-bus: up to 6.5 Mbit/s

Absolute Maximum Ratings:

  • Max supply voltage (VDD): 6.5 V
  • Max battery supply voltage (VBAT): 6.5 V
  • Max supply current (IDD): 50 mA
  • Max input voltage (Vi): 6.5 V
  • Max output current (IO): 10 mA (20 mA at pin SDA/CE)
  • Max total power dissipation: 300 mW
  • Storage temperature: -55 to +85 °C
  • ESD: ±4000 V HBM, ±1250 V CDM

Key Specs:

  • Typical accuracy (PCF2129T): ±3 ppm from -30 °C to +80 °C
  • Typical accuracy (PCF2129AT): ±3 ppm from -15 °C to +60 °C
  • Supply current: typ. 0.70 μA at VDD = 3.3 V
  • Clock operating voltage: 1.8 V to 4.2 V
  • I²C-bus speed: 400 kHz Fast-mode
  • SPI-bus speed: max 6.5 Mbit/s
  • Latch-up current: max 200 mA
  • Ambient operating temperature: -40 to +85 °C

Features:

  • Temperature Compensated Crystal Oscillator with integrated capacitors and 32.768 kHz quartz crystal
  • Year, month, day, weekday, hours, minutes, seconds, and leap year correction
  • Timestamp function with interrupt capability; two event types detected on one multilevel input pin (e.g., tamper detection)
  • Selectable I²C-bus or 3-line SPI-bus interface
  • Battery backup input with switch-over circuitry, battery-backed output voltage, and battery low detection
  • Power-On Reset Override (PORO)
  • Oscillator stop detection
  • Open-drain interrupt output
  • Programmable 1 second or 1 minute interrupt
  • Programmable watchdog timer with interrupt
  • Programmable alarm with interrupt
  • Programmable square-wave clock output (32.768 kHz down to 1 Hz)
  • Aging offset register for crystal aging correction
  • UL Recognized Component (PCF2129AT and PCF2129T)

Applications:

  • Electronic metering for electricity, water, and gas
  • Precision timekeeping
  • Access to accurate time of day
  • GPS equipment to reduce time to first fix
  • Applications requiring accurate process timing
  • Products with long automated unattended operation time

Package:

  • SO16 (SOT162-1), 16 leads, 7.5 mm body width — PCF2129T
  • SO20 (SOT163-1), 20 leads, 7.5 mm body width — PCF2129AT

PCF2129T Features

  • UL Recognized Component (PCF2129AT and PCF2129T)
  • 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 I 2 C-bus interface
  • Three 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

1 The definition of the abbreviations and acronyms used in this data sheet can be found in Section 20.

  • Low supply current: typical 0.70 μA at VDD = 3.3 V

PCF2129T Applications

  • Electronic metering for electricity, water, and gas
  • Precision timekeeping
  • Access to accurate time of the day
  • GPS equipment to reduce time to first fix
  • Applications that require an accurate process timing
  • Products with long automated unattended operation time

PCF2129T Pin Configuration

Table 3. Pin description of PCF2129

Input or input/output pins must always be at a defined level (VSS or VDD) unless otherwise specified.

SymbolPin - PCF2129ATPin - PCF2129TDescription
SCL11combined serial clock input for both I 2 C-bus and SPI-bus
SDI22serial data input for SPI-bus connect to pin V SS if I 2 C-bus is selected
SDO33serial data output for SPI-bus, push-pull
SDA/CE44combined serial data input and output for the I 2 C-bus and chip enable input (active LOW) for the SPI-bus
IFS55interface selector input connect to pin V SS to select the SPI-bus connect to pin BBS to select the I 2 C-bus
TS66timestamp input (active LOW) with 200 kΩ internal pull-up resistor (R PU )
CLKOUT77clock output (open-drain)
V SS88ground supply voltage
n.c.9 to 169 to 12not connected; do not connect; do not use as feed through
INT1713interrupt output (open-drain; active LOW)
BBS1814output voltage (battery backed)
V BAT1915battery supply voltage (backup) connect to V SS if battery switch over is not used
V DD2016supply voltage

PCF2129T Typical Application

For information about application configuration, see [1].

All information provided in this document is subject to legal disclaimers.

© 2022 NXP B.V. All rights reserved.

Accurate RTC with integrated quartz crystal for industrial applications

PCF2129T Package Information

OUTLINE VERSIONREFERENCES - IECREFERENCES - JEDECREFERENCES - JEITAEUROPEAN PROJECTIONISSUE DATE
SOT163-1075E04MS-01399-12-27 03-02-19

© 2022 NXP B.V. All rights reserved.

Accurate RTC with integrated quartz crystal for industrial applications

OUTLINE VERSIONREFERENCES - IECREFERENCES - JEDECREFERENCES - JEITAEUROPEAN PROJECTIONISSUE DATE
SOT162-1075E03MS-01399-12-27 03-02-19

© 2022 NXP B.V. All rights reserved.

Variants on the same datasheet

These parts have exact links to the same datasheet. They are candidates to compare, not verified drop-in replacements; check package, pinout and electrical limits.

Part NumberManufacturerPackage
PCF2129NXP Semiconductors—
PCF2129ANXP Semiconductors—
PCF2129ATNXP SemiconductorsSO20
PCF2129AT/2NXP SemiconductorsSO20
PCF2129AT/2,518NXP Semiconductors20-SOIC (0.295", 7.50mm Width)
PCF2129T/2NXP SemiconductorsSO16
PCF2129T/2,518NXP Semiconductors16-SOIC (0.295", 7.50mm Width)

Other Integrated Circuits

All Integrated Circuits datasheetsAll NXP Semiconductors datasheets (189)

Data on this page is extracted from publicly available manufacturer datasheets using automated tools including AI. It may contain errors or omissions. Always verify specifications against the official manufacturer datasheet before making design or purchasing decisions. See our Terms of Service. Rights holders can submit a takedown request.

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