Circuit Design is a Japanese manufacturer of quality radio modules. It is focused to development and manufacturing of transmitters, receivers, transceivers, radio modems and audio modules in license free sub-GHz bands. Thanks to low RF output power, high sensitivity, narrow band and usage of discrete parts in compact metal package the modules have superior features, long range and low power consumption. They are suitable for industrial applications, wireless control, telemetry, alarms and security technics and for all other applications where wireless transfers with high reliability are needed.

Transmitters, receivers and transceivers

These modules contain just optimized RF part. The user can connect them to any equipment and use any protocol and his own digital coding and control.

FSK modulation allowing to select 11, 32 or 128 channels, with 12.5 or 25 kHz step and 25 kHz gap is used. Frequency PLL/VCO synthesizer controlled by the microrontroller allows to achive better parameters in comparison with similar RF modules wit SAW resonators.

Output RF power is selectable 1 and 5 or 10 mW, signal range up to 600 m and data rate selectable up to 9600, 4800 or 2400 b/s. Transceiver Tx/Rx switching is typically 15 ms.

There is even a miniature low cost version with dimensions 22 x 12 x 6 mm and very low power consumption.

RF modems

Radio modems for bidirectional serial data transfer are controlled via commands. The user need not take care about the protocol and RF communication control.

The modems have simple UART interfaces with max. baud rate 57.6 kBd for data and commands passing. The commands are designed especially for wireless applications (control, communications, data transfers etc.). They allow to change RF channel simply (64 or 127 channels with 25 kHz or 12.5 kHz steps), parameters of the UART interface and so on. The modems have also additional features such as correction of failures, repeater and automatic acknowledge. Thus, simple tasks as well as complex network systems can be realized in this way.

Modems have output power 1 and 10 mW, range up to 600 m and data rate 4800 or 9600 b/s.

Boards realizing various interfaces (RS232, USB, LAN) are available for the modems.

RF audio modules

Modules are intended for high quality wireless transfer of analog audio signal from transmitter microphone input to receiver audio output. They are equipped with the noise reduction systems including the companders/expanders. Single channel version with selection from four frequencies is available which allows to run more systems in the same location. The multichannel version offers 15 channels with 125 kHz step. For 2 mW oputput power the range is up to 50 m (line of sight). Audio frequecny range is 50 Hz to 15 kHz or 13 kHz.

Accessories

For development demo/test boards are available, some of them with simple control and indication, without necessity of programming, others with microcontrollers fully programmable by the ISP method, with software. Antennas (flexible, streight or joint), coaxial cables, conversion devices and connectors are also available.

RF transmitters and receivers

• CDP-TX-02F(P)-R, CDP-RX-02F(P)-R
  • 434 MHz, 128 channels, 1 mW/10 mW, range 500 m, 4800 b/s
• CDP-TX-02E(P)-R, CDP-RX-02E(P)-R
  • 1 mW/10 mW, range 500 m
  • 434 MHz, 32 channels, 4800 b/s, 457 MHz, 32 channels, 2400 b/s
    458 MHz, 11 channels, 4800 b/s
• CDP-TX-05M-R, CDP-RX-05M-R
  • 434 MHz and 869 MHz
  • fixed channel, selectable within four preprogrammed channels
  • 100-4800 b/s, 10 mW/5 mW,range 600 m
  • miniature, low power consumption

RF transceivers

• STD-302N-R
  • 335 MHz, 419 MHz, 429 MHz, 434 MHz,
    447 MHz, 458 MHz, 869 MHz
  • 10 mW / 5 mW (869 MHz) / 1 mW (335 MHz)
  • 4800 or 9600 b/s
  • 25 kHz channels, SW selectable (via serial line)
  • Fast Tx/Rx switching

RF modems

• MU-2-R
  • UART interface (max. 57.6 kb/s), protocol with simple commands
  • ISM 434 MHz, FSK, 127 channels
  • 1 mW/10 mW, narrow band, long range, 4800 b/s
  • Fast Tx/Rx switching, low power consumption (Tx 42 mA, Rx 22 mA)
  • Temperature range -20 ^oC to +65 ^oC, power supply 3.0 V to 5.5 V
• MU-1-R
  • UART interface (max. 57.6 kb/s), protocol with simple commands
  • ISM 434 MHz, FSK, 64 channels
  • 10 mW, narrow band, long range, 9600 b/s
  • Fast Tx/Rx switching, low power consumption (Tx 46 mA, Rx 32 mA)
  • Temperature range -20 ^oC to +65 ^oC, power supply 3.0 V to 5.5 V

RF audio modules

• WA-TX-01-R, WA-RX-01A-R
  • Single channel audio RF transmitter and receiver
  • Selectable 863.125 MHz, 863.625 MHz, 864.500 MHz, 864.875 MHz
  • 2 mW, consumption 25/30 mA, voice range 50 Hz to 15 kHz
• WA-TX-03-R, WA-RX-03-R
  • Audio RF transmitter and receiver, 863 - 865 MHz, 15 channels/125 kHz
  • 2 mW, consumption 45/70 mA, voice range 50 Hz to 13 kHz

Useful links

Circuit Design