CMX994/994A/994E/994G
– RF Direct Conversion Receiver ICs
CMX994/994A/994E/994G
– RF Direct Conversion Receiver ICs
** Not recommended for new designs, but an alternative new part is available here.**
The CMX994, CMX994A, CMX994E, CMX994G is a family of direct conversion receiver ICs with PowerTrade™; the ability to dynamically select power against performance modes to optimise operating trade-offs.
CMX994 – Standard and low power modes
CMX994A – Standard and additional low power modes
CMX994E – Enhanced, standard and low power modes
CMX994G – Enhanced, standard and low power modes, 30MHz guaranteed performance
The CMX994/A/E/G offer exceptional blocking performance, typical values are in the range 98dB to 102dB depending on the measurement method. All three devices include a broadband LNA with gain control followed by a high dynamic range, very high IIP2, I/Q demodulator. The receiver baseband section includes amplifiers and precise, configurable bandwidth, baseband filter stages. LO generation is provided by an integer-N PLL and a VCO negative resistance amplifier; an external LO may also be used. LO dividers are provided for flexible multi-band operation.
The CMX994/A/E/G operates from a single 3.3V supply over a temperature range of –40°C to +85°C and are available in a small 40-pin VQFN (Q4) package.
Devices are available through our Distributor Network.
Features of the CMX994/994A/994E/994G – RF Direct Conversion Receiver ICs include:
- Direct Conversion Receiver Family with PowerTrade™ Flexible Power vs. Performance Modes – CMX994 – Standard and Low Power Modes – CMX994A – Standard and Additional Low Power Modes – CMX994E – Enhanced, Standard and Low Power Modes – CMX994G – Enhanced, Standard and Low Power Modes, 30MHz guaranteed performance for radios operating down to 30MH
- Rx Single Conversion to Zero IF, Near-zero IF or Low IF; Zero IF Eliminates Image Responses
- Very High Mixer IIP2 for Practical Zero IF Receiver
- 100MHz to 1000MHz I/Q Demodulator (CMX994EF) 100MHz to 940MHz I/Q Demodulator (CMX994) Extended Operation down to 50MHz or 30MHz (CMX994G)
- LNA with Gain Control
- Precise Filtering with 1:2:4 Bandwidth Select Control
- Mixer Bandwidth up to 20MHz
- Local Oscillator – LO synthesiser – VCO Negative Resistance Amplifier – Rx LO Divide by 2, 4 or 6 Modes – Tx LO Output with Divide by 1, 2, 4 or 6 Modes
- Small Size 40-pin VQFN Package
Applications the CMX994/994A/994E/994G – RF Direct Conversion Receiver ICs can be used for:
- Analogue/digital Multi-mode Radio
- Software Defined Radio (SDR)
- Data Telemetry Modems
- Satellite Communications
- Constant Envelope and Linear Modulation
- Rx Function Compatible with CMX998
- Cartesian Feedback Loop Transmitter
- Narrowband e.g.: 25kHz, 12.5kHz and 6.25kHz
- Wideband Data e.g. >1MHz Bandwidth
Power Supply Requirements for the CMX994/994A/994E/994G – RF Direct Conversion Receiver ICs:
- 3.0 to 3.6 V
Frequency Estimation for a VCO using a Negative Resistance Amplifier
Application Note describing how to estimate the operating frequency of VCO designs using a negative resistance amplifier. An Excel spreadsheet that automates the calculation is available below.
Excel Spreadsheet – Frequency Estimation for a VCO using a Negative Resistance Amplifier
An Excel spreadsheet that calculates the operating frequency of VCO designs using a negative resistance amplifier. An Application Note describing the process is available above.
CMX994/A/E Interference Immunity
Through clarification of blocking and second order intermodulation performance, together with empirical measurement, this app note illustrates the excellent characteristics of the CMX994/CMX99A/CMX994E marking its suitability for professional radio designs.
CMX994A / CMX994E 400MHz to 470MHz Operation
An Application Note demonstrating through the use of a simple RF matching circuit for the CMX994A and CMX994E devices in 400MHz to 470MHz band applications. Comparative measurements are made with the existing EV9942A/E and DE9945A Evaluation Boards throughout and results provided.
CMX994/A/E LNA Performance and Applications
An application note that describes the performance characteristics of the CMX994’s LNA and the benefits of this device for typical PMR radio designs.
CMX994A / CMX994E Alternative Operating Bands
This application note suggests circuit values for the 450 to 520 MHz band and the 136 to 174 MHz band. It accompanies the existing 400 to 470 MHz operation application note (AN/RF/CMX994EF 440 to 470) and is based around the CM994A/E evaluation platform (EV9942A/E).
CMX994 – Demonstration Video Scripts
These scripts are used in the “CMX994 Demonstration” video. The scripts guide the user through Tx/Rx frequency trimming, Rx I/Q DC offset calibration, Rx Equalizer training, Tx I/Q DC offset calibration, and formatted data transfer.
| DE9941A | The DE9941A is a credit-card sized, fully functional, UHF wireless data modem using the CMX994E Direct Conversion Receiver, the CMX998 Cartesian Feedback Loop Transmitter and the CMX7364 High Performance Multi-mode Wireless Data Modem. Full design data and test scripts are available to download from the DE9941A Product Page. | DE9941A_Product_Page |
| EV9942A/9942E | Two versions of the Evaluation Kit are available allowing the user to investigate all aspects of the chosen CMX994, high-performance direct conversion receiver. A common PC-based application identifies the CMX994 version and starts an interactive GUI for configuration and control. A separate hi-res schematic is available for both versions of the EV9942. | EV9942_Product_Preview |
C-BUS Guides
Guides to operation and interfacing
EV9942 Evaluation Software
A common GUI-based application for the EV9942/EV9942A/EV9942E Evaluation Kits. A PE0003 Universal Interface Card is required to use this application. Version 4.1
EV9942 Quick Start
A simple guide to help users get started evaluating the EV9942, EV9942A and EV9942E Evaluation Kits. Ver.2
EV9942A Board Schematics
EV9942A Board high-resolution schematic. Ver.A03
EV9942E Board Schematics
EV9942E Board high-resolution schematic. Ver.A02
PE0003 Driver
PE0003 USB driver for Windows. Version 1.0
EV9942A BOM
EV9942A Board BOM Ver.A03
EV9942E BOM
EV9942A Board BOM Ver.A02
CMX994 FAQ
Q, Are the CMX994A, CMX994E and CMX994G devices pin compatible with the CMX994 in my digital radio?
A, Yes all four devices are pin and function compatible. However, if the CMX994A, CMX994E or CMX994G are to be fitted into an existing CMX994 design, it is recommended that the new extended DC Offset register is used.
There are additional benefits in adopting the CMX994A, CMX994E and CMX995G they include additional low power operating modes, enhanced mixer IM capability and guaranteed 30MHz operation, these are illustrated below. A means of confirming device type by a software read is also shown.
Quick Product Selector
Looking for extra information?
Get in touch with your questions and one of the team will get in touch shortly.
Looking for one of our distributors?
Find your local distributor here
Get in touch
"*" indicates required fields
