RX-4803SA (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 )
TEST Input Use by the manufacture for testing.
( Do not connect externally. )
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)

The metal case inside of the molding compound may be exposed on the top or bottom of this product.
This purely cosmetic and does not have any effect on quality, reliability or electrical specs.

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