RX-4803LC (Built-in 32.768kHz-DTCXO, High Stability Serial-Interface Real Time Clock Module)

  • Built in frequency adjusted 32.768kHz crystal unit and DTCXO.
  • 1/100s resolution Time register
  • Interface Type
    4-wire serial interface
  • Interface voltage range
    1.6V to 5.5V
  • Temp. compensated voltage range
    2.2V to 5.5V
  • Clock supply voltage range
    1.6V to 5.5V
  • Selectable clock output (32.768kHz, 1024Hz, 1Hz)
  • The various functions include full calendar, alarm, timer, EVIN input.
  • Epson prepared Linux driver for development

The registered trademark Linux® is used pursuant to a sublicense from LMI(Linux Mark Institute)

Complies with EU RoHS directive.


Block diagram

Block diagram


  • High Stability
    • UA ± 3.4 × 10-6 / -40°C to +85°C
    • (Equivalent to ±9seconds of month deviation)
    • UB ± 5.0 × 10-6 / -40°C to +85°C
    • (Equivalent to ±13seconds of month deviation)
    • UC ± 5.0 × 10-6 / -30°C to +70°C
    • (Equivalent to ±13seconds of month deviation)
    • AA (+5 ± 5.0) × 10-6 / +25°C
  • High Resolution:1/100s Time register with capture buffer
  • 32.768kHz frequency output function
    • FOUT pin output (C-MOS output), CL=30pF
    • Output selectable: 32.768kHz, 1024Hz, 1Hz
  • The various interrupt
    • Timer Function can be set between 1/ 4096second and 4095 minutes.
    • Alarm Function can be set to day of week, day, hour, or minute.
    • EVIN input.
  • Time synchronize function with 1PPS signal input
  • Register compatibility:upper compatible with RX-4801.

*It is possible to use it by the terminal connection as 32.768kHz-DTCXO.

Specifications *Refer to application manual for details.

Electrical Characteristics

Item Symbol Condition Min. Typ. Max. Unit
Interface voltage VDD Interface voltage 1.6 3.0 5.5 V
Temp. compensated Voltage VTEM Temp. compensated voltage 2.2 3.0 5.5 V
Clock supply voltage VCLK - 1.6 3.0 5.5 V
Operating temperature TOPR No condensation -40 +25 +85 °C
Stability Δf/f UA Ta = -40°C to +85°C ±3.4*1 ×10-6
UB Ta = -40°C to +85°C ±5.0*2
UC Ta = -30°C to +70°C
AA Ta = +25°C 5 ± 5.0*3
Current consumption (1) IDD1 Backup Mode
FOUT output : OFF
VDD = 5V - 0.75 3.4 µA
Current consumption (2) IDD2 VDD = 3V - 0.75 2.1

*1) Equivalent to ±9seconds of month deviation.
*2) *3) Equivalent to ±13seconds of month deviation. (excluding offset)

32.768kHz-DTCXO Frequency temperature characteristics (Example)

Frequency temperature characteristics


Pin function

Signal Name Input/Output Function
CE Input The chip enable input pin.
CLK Input The shift clock input pin for serial data transfer.
FOUT Output The pin outputs the reference clock signal.
( CMOS output )
VDD - Connected to a positive power supply
FOE Input The input pin for the FOUT output control.
EVIN Input External event input.
( Do not make this pin OPEN.)
/ INT Output Interrupt output (N-ch. open drain).
GND - Connected to a ground
T2(VPP) - Use by the manufacture for testing.
( Do not connect externally.)
DO Output The data output pin for serial data transfer.
DI Input The data input pin for serial data transfer.

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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