*The CDP-02N models are hereinafter referred to as CDP-02N (for transmitters and
receivers), CDP-TX-02N (for transmitters) and CDP-RX-02N (for receivers), unless
The CDP-02N is suitable for various application fields such as wireless data communication,
remote control, telemetry or wireless security systems. It is easy to use and integrate into
The CDP-02N is equipped with a frequency synthesizer system with micro controller.
Available frequency ranges are from 433.875 MHz to 434.650 MHz (32 channels:16 ch x 2
groups) and from 458.525 MHz to 458.775 MHz (11 channels). The compact size, low
operating voltage and frequency selectability of the CDP-02N make it ideal for various
applications where its interference rejection and practical distance range is far better than
similar RF modules based on wide band SAW-resonator frequency generators.
Serial digital data (TTL level), such as pulse width modulation signals and signals from
standard encoder-decoder circuits of the given AF bandwidth, can be transmitted.
CDP-TX-02N transmitter module
The CDP-TX-02N is a UHF FM-narrow band transmitter with PLL synthesizer and micro
controller for high frequency stability and channel selectability. Modern SMT technology gives
it its small size - much smaller than a match box.
The narrow band FM modulation (direct FSK) enables efficient use of the available RF
spectrum. Different modules can operate in a 25 KHz channel spacing scheme unlike SAW
resonator transmitters which use a very broad band of the frequency spectrum.
The CDP-TX-02N can transmit any 5 V digital input data in the specified frequency range.
Analog data is digitized by the internal comparator.
In about 80 msec (90 msec for 458 MHz) after the transmitter is connected to a power source,
PLL is locked and data can be transmitted without further control or synchronization.
Transmission is physically achieved by a flexible Lambda/4 antenna connected to the module.
The amount of radiated power and the surrounding of the antenna influences directional
behavior. Installation in a bigger metal housing with a ground connected to the transmitter
module housing and the transmitter antenna placed in an upright position outside the metal
housing will reduce the antenna impedance and increase the radiated power. For best
performance in a user system general rules of radio frequency technology should be taken
The same considerations should also be applied to the receiver.
4 Circuit Design, Inc.