PCF2123 Datasheet - NXP Semiconductors

PCF2123 SPI Real time clock/calendar

The PCF2123 is a CMOS1 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.

PCF2123 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 C

* Resolution: seconds to years

* Watchdog functionality

* Freely programmable

PCF2123_NXPSemiconductors.pdf