DSSS Low Power Radio TransceiverSTD-503

The STD-503 is a 2.4 GHz transceiver enclosed in a small compact shield casing designed for industrial applications. The transceiver uses Direct Sequence Spread Spectrum (DSSS) modulation and true diversity circuit, enabling reliable communications even in the congested 2.4 GHz band.

The STD-503 complies with the European EN300 440, U.S FCC Part 15.247, Canadian ISED RSS-210 and Japanese ARIB STD-T66, making it ready for the global market.

Low power consumption and battery operation give the STD-503 the performance demanded for applications where long range and reliability are required.

The transceiver uses a transparent data interface to enable users to communicate using their own protocols. The module's configuration can be set easily via the UART interface using dedicated commands.

Circuit Design developed an onboard ASIC containing SS correlator (a key part of spread spectrum communication). This ensures long term supply for industrial applications



  • CE, FCC, ISED and ARIB conformity certification
  • Uses direct sequence spread spectrum (DSSS) modulation
  • Channel stepping option controlled via CHC pin
  • A true diversity receiver ( two built-in receiver circuits)
  • Module settings using dedicated commands
  • Data communication uses a transparent interface
  • Low power operation 77 channels
  • Communication LOS: 300 m
  • Onboard temperature sensor


  • Industrial telecontrol
  • Telemetry Systems

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Channel Programmable Narrow Band FM Transceiver


High Performance Channel Programmable Transceiver



Parameter Specification Remarks
Applicable standard EN 300 440
FCC part 15.247
Communication method Simplex
Transmission method Direct sequence spread spectrum
Emission type F1D FSK
Frequency 2402.5 to 2478.5 MHz
Channel spacing 1 MHz
Data bit rate 19.2 kbps
Chip rate 288 kcps
RF connectors MHF x 2
Spreading code 15 Chips M-sequence
( 111101010001100 )
temperature range
-20 to +65 degree C No dew condensation
Supply voltage 3.3 to 5.0 V DC Absolute max. voltage
5.5 V
Supply current 48 mA typ. (TX)
55 mA typ. (RX)
Dimension 40 x 29 x 5.5 mm
Weight 10 g

Transmitter Part

Parameter Specification Remarks
RF output power < 10 mW e.i.r.p.
TX data input Digital L = GND, H = Vref

Receiver Part

Parameter Specification Remarks
RF Input level < -13 dBm
Receiver sensitivity -93 dBm 19.2 kbps BER 0.1%
RX data output Digital L = GND, H = Vref


Parameter Specification Remarks
RF Data Interface
Port DO / DI / CLK
Data bit rate 19.2 kbps Sync: CLK terminal
Command Interface
Port TXD / RXD
Interface UART communication (RS232C format)
Communication method Asynchronous
UART bit rate 19.2 k / 38.4 k / 57.6 kbps
Flow control None
Other parameters Data length: 8 bits / Parity (None) / Stop bits 2

External View


Data Sheet

Version 1.5 PDF

Operation Guide

Version 2.2 PDF


Operation Guide

Version 1.0

Evaluation Tools: TB-STD503

The TB-STD503 evaluation board allows you to evaluate the STD-503 or STD-502-R module and perform range, data packet and switching signal transmission tests.
Onboard LEDs, CH switch, ID switch and push buttons allow you to easily make switching signal transmission tests and packet tests with packet error indication.

The TB-STD503 can also perform pre-programmed frequency hopping sequences by setting the onboard rotary switch.
The boards do not include modules STD-502-R / STD-503. Please order them separately if needed.


  • 4-push buttons and output LEDs.
  • Channel setting and ID switches
  • External input/output pins
  • Receiving antenna LED indicatorPacket test function
  • One way / two way communication mode setting
  • 16 pre-programmed frequency hopping sequences (for STD-503 module only)
  • For use with STD-502 or STD-503 module.

External View

Board x 1
Socket x 2
Spacer x 4



Sleeve Antenna

Frequency: 2.4 GHz
Gain: 2dBi


...more info


Whip Antenna

Frequency: 2.4 GHz
Gain: 0dBi


...more info


Whip antenna swivel type

FCC approval for use with STD-503 : Yes

...more info


Waterproof swivel type

...more info


MHF - RP-SMA conversion cable

Length: 150 mm
Connector: MHF - RPSMA

...more info