PCF2129AT/1,518

Real Time Clock Serial 3-Wire, I2C, SPI Clock/Calendar 20Pin SO T/R

Overview

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.

MoreLess

## 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

## Target 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

## Features