RX-4571LC (Low Backup Voltage Serial-Interface Real Time Clock Module)

  • Built in frequency adjusted 32.768kHz crystal unit.
  • Interface Type
    3-wire serial interface
  • Operating voltage range
    1.6V to 5.5V
  • The wide voltage for time keeping
    1.0V to 5.5V / Ta=+25°C
  • Low backup current
    0.32µA(Typ.) / 3V
  • 32.768kHz frequency output function
    C-MOS output With OE pin
  • Real-time clock function Clock/calendar function, auto leap year correction function,
    Alarm and Timer interrupt function, etc.

Complies with EU RoHS directive.


Block diagram

Block diagram


  • 32.768kHz frequency output function
    • FOUT pin output(C-MOS output), CL=30pF
  • Timer function
    • Timer function which can be set up between 1/4096second and 4095minutes.
  • Alarm function
    • Alarm function can be set to any combination of day, day of week, hour, or minute.

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 Ta=+25°C 1.0 3.0 5.5 V
Ta=-40 to +85°C 1.1 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
1Max. s

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

Current consumption characteristics

*Ta=-40°C to +85°C

Item Symbol Conditions Min. Typ. Max. Unit
Current consumption lBK CE=GND

FOUT;output OFF(Hi-z)
VDD=5V - 0.40 1.00 µA
VDD=3V - 0.32 0.95
l32k CE=GND

FOUT; 32.768kHz output ON
VDD=5V - 8.0 14.0 µA
VDD=3V - 5.0 8.5


Pin function

Signal Name Input/Output Function
CE Input The chip enabled input pin 0. ( It has a built -in pull-down resistance )
CLK Input The shift clock input pin for serial data transfer.
DIO Bi-directional The data input / output pin for serial data transfer.
FOUT Output 32.768kHz clock output pin with the output control function. (C-MOS)
FOE pin control the condition of FOUT with FSEL1-bit, FSEL0-bit, etc.
FOE Input
/ IRQ Output Interrupt output (N-ch open drain)
VDD - Connected to a positive power supply.
GND - Connected to a ground.

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).

Page Top