RX8900CE :I2C-Bus Interface Real Time Clock Module (Built-in 32.768 kHz-DTCXO, High Stability and Power Switching)

• Built in frequency adjusted 32.768 kHz crystal unit and DTCXO.
• Interface Type
  I²C-Bus interface (400kHz)
• Interface voltage range
  2.5V to 5.5V
• Temp. compensated voltage range
  2.0V to 5.5V
• Clock supply voltage range
  1.6V to 5.5V
• Selectable clock output(32.768 kHz, 1024 Hz, 1 Hz)
• The various functions include full calendar, alarm, timer, temp. sensor function.
• Epson prepared Linux driver and evaluation board for development
  https://www5.epsondevice.com/en/information/support/linux_rtc/
  The registered trademark Linux® is used pursuant to a sublicense
  from LMI(Linux Mark Institute)
  https://www5.epsondevice.com/en/information/support/rtc_evaboard/


• Vide How to use Real Time Clock Module evaluation board (RX8900CE, RX8804CE)

Block diagram

Overview

• High Stability
  • UA ± 3.4 x 10^-6 / -40 °C to +85 °C ( Equivalent to ±9 seconds of month deviation )
  • UB ± 5.0 x 10^-6 / -40 °C to +85 °C ( Equivalent to ±13 seconds of month deviation )
  • UC ± 5.0 x 10^-6 / -30 °C to +70 °C ( Equivalent to ±13 seconds of month deviation )
• 32.768 kHz frequency output function
  • FOUT pin output (C-MOS output), CL=30 pF
  • Output selectable: 32.768 kHz, 1024 Hz, 1 Hz
• Available automatic battery backup switch-over function
  • Charge from VDD to backup battery connected to VBAT is possible.
    VDD voltage drop(VDET3) detection and automatically switches to the backup battery.
    This circuit is optimal to backup with a secondary battery and a large capacitor.
• Timer function
  • Timer period is adjustable in 1/4096 second from 4095 minutes
• Alarm function
  • Available dual-alarm, weekly and monthly
• Temp. sensor function
  • Available readout temperature data from embedded temp sensor. (Bank.2_Add17h)

Specifications (characteristics)

Refer to application manual for details.

*1 Equivalent to ±9 seconds of month deviation.
*2 Equivalent to ±13 seconds of month deviation.
*3 Please contact us about +85°C < T_OPR

32.768 kHz-DTCXO Frequency temperature characteristics (Example)

Pin function

Terminal connection/External dimensions

Footprint (Recommended)