RX-8571LC (Low Current Consumption I2C-Bus Interface Real Time Clock Module)

  • Built-in frequency adjusted 32.768kHz crystal unit.
  • Interface Type
    I2C-Bus Interface(400kHz)
  • Operating voltage range
    1.6V to 5.5V
  • Wide voltage for timekeeping
    1.3V to 5.5V
  • Low backup current
    220nA / 3V(Typ.)
  • 32.768kHz frequency output function
    C-MOS output With Control Pin
  • Built in user RAM
    128bit(8bit x 16, SRAM)
  • The various functions include full calendar, alarm, timer,etc.
    (Long-running timer : 65535 hours)

Complies with EU RoHS directive.


Block diagram

Block diagram


  • 32.768kHz frequency output function
    • FOE pin enable output on/off control.
    • Output frequency can be selected as 32.768kHz, 1024Hz, 1Hz.
  • Timer function
    • Timer function can be set up between 1/4096second and 65535hours.
    • Timing period are 1h, 1min, 64Hz, 4096Hz.
    • It is recorded automatically to TF-bit at the time of
      event occurs, and possible to output with /IRQ pin output.
  • Alarm function
    • Alarm function can be set to day of week, day, hour, or minute.
    • It is recorded automatically to AF-bit at the time of
      event occurs, and possible to output with /IRQ pin output.
  • User RAM
    • 128bit (8bit x 16,SRAM)

Specifications *Refer to application manual for details.

Recommend Operating Conditions

Item Symbol Condition Min. Typ. Max. Unit
Power voltage VDD - 1.6 3.0 5.5 V
Clock voltage VCLK - 1.3 3.0 5.5 V
Operating temperature TOPR - -40 +25 +85 °C

Frequency characteristics

Item Symbol Condition Rating Unit
Frequency tolerance Δ f/f Ta=+25°C
5±23 * ×10-6
Oscillation start up time tSTA Ta=+25°C
1 Max. s

* Please ask for tighter tolerance.( Equivalent to ±1 minute of monthly deviation )

Current consumption characteristics

Item Symbol Conditions Min. Typ. Max. Unit
- 220 400 nA
VDD =3.0V
Ta= -40°C to +85°C
- - 550 nA


Terminal connection / External dimensions

Terminal connection External dimensions

(Unit: mm)

Stop using the glue
Any glue must never use it after soldering LC-package to a circuit board.
This product has glass on the back side of a package.
When glue invasions between circuit board side and glass side, then glass cracks by thermal expansion of glue.
In this case a crystal oscillation stops.Consider glue abolition or glue do not touch to LC-package

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).

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