RX8901CE (RTC Module)High stability, Low current consumption, Time stamp function

The RX8901CE is a RTC module with an integrated 32.768 kHz digital temperature compensated crystal oscillator (DTCXO). It includes various functions such as a time stamp function that can record up to 32 dates and times when an external or internal event occurs, as well as the basic RTC functions such as time and calendar, time alarm, wakeup timer, and time update interrupts. With the combination of an auto power switching function, which includes a control circuit to prevent reverse current to the main power supply, a continuous temperature-corrected 32.768 kHz clock generation, and Seiko Epson's original low current consumption technology, the RX8901CE realizes long battery life on various systems.

Solutions for Lowering System Power and Improving Time Accuracy


  • Built in frequency adjusted
    32.768 kHz crystal unit
  • Interface Type
    I2C-Bus interface
  • Low backup current
    240 nA Typ. / 3 V
  • Auto power switching function
    Automatically switches to backup power supply by
    monitoring the VDD voltage
  • Time stamp function
    32 times max. stamped from year to 1/1024 seconds.
  • Time update interruption
    Hourly, minutely, and secondly
  • Alarm interruption in Day, date,
    hour, minute, second
  • Auto repeat wakeup timer interruption
  • Self-monitoring interruption
    Crystal oscillation stop.
    VBAT low, VDD low.
  • Links to convenient toolsClick here
  • Links to Video contentsClick here

Complies with EU RoHS directive.Complies with EU RoHS directive.


Block diagram

Block diagram

Specifications (characteristics)

Refer to application manual for details


Product name and number



Pin function

Terminal connection External dimensions

External dimensions / Terminal connection

Terminal connection External dimensions

(Unit: mm)

Footprint (Recommended)


(Unit: mm)

To maintain stable operation, provide a 0.1uF by-pass capacitor
at a location as near as possible to the power source terminal of the crystal product (between Vcc - GND)

Video contents: Feature of RX8901CE / RX4901CE

Video contents: RX8901CE: Example of Use Cases

White paper: Tamper Detection using a RTC Module

White paper: kHz-band DTCXO timekeeping accuracy in a temperature changing environment

White paper: RTC sub second functions and applications

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