PCF2129AT/2,518

Real Time Clock Overview

The PCF2129AT/2,518 is a CMOS Real Time Clock (RTC) and calendar IC manufactured by NXP USA Inc. It features an integrated Temperature Compensated Crystal Oscillator (TCXO) with a 32.768 kHz quartz crystal optimized for high accuracy and low power consumption. The device supports selectable I²C-bus or SPI-bus interfaces, operates within a voltage range of 1.8 V to 4.2 V, and functions in temperatures from -40 °C to +85 °C. Typical accuracy is ±3 ppm from -15 °C to +60 °C. It includes battery backup switch-over, timestamping, watchdog timer, alarm, and interrupt capabilities.

Real Time Clock Feature Summary

• Integrated TCXO with 32.768 kHz quartz crystal providing typical accuracy of ±3 ppm (-15 °C to +60 °C)
• Selectable I²C-bus (400 kHz Fast-mode) or SPI-bus (up to 6.5 Mbit/s) interface
• Battery backup switch-over circuitry with battery low detection function
• Programmable alarm, watchdog timer, and timestamp function with interrupt capability

Real Time Clock Applications

• Electronic metering for electricity, water, and gas
• GPS equipment to reduce time to first fix
• Products requiring long automated unattended operation time

Real Time Clock Procurement Notes

Verify the ordering part number PCF2129AT/2,518 corresponds to the SO20 package variant. Confirm the packing method matches the reel specification (13" Q1 DP). Ensure the temperature range requirement aligns with the specified -40 °C to +85 °C operating conditions before procurement.

Real Time Clock Selection Notes

Select the PCF2129AT variant when using the SO20 package. Choose between I²C or SPI interface based on system requirements; configure the IFS pin accordingly. Ensure supply voltage remains within 1.8 V to 4.2 V. Consider the ±3 ppm accuracy specification for precision timing applications.

Real Time Clock Part Context

The PCF2129 series includes the PCF2129T (SO16 package) and PCF2129AT (SO20 package). Both variants share identical functional specifications but differ in physical package dimensions and lead counts. The /2,518 suffix indicates the specific ordering code for the reel packaging configuration.

Real Time Clock Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.