RF Direct Conversion Receiver ICs
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
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 (CMX994A/E)
100MHz to 940MHz I/Q Demodulator (CMX994)
Extended Operation down to 50MHz
LNA with Gain Control
Precise Filtering with 1:2:4 Bandwidth Select Control
Mixer Bandwidth up to 20MHz
- 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
Analogue/digital Multi-mode Radio
Software Defined Radio (SDR)
Data Telemetry Modems
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
The CMX994/CMX994A/CMX994E is a family of direct conversion receiver ICs with PowerTrade™, the ability to dynamically select power vs. performance modes to optimise operating trade-offs.
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
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 devices operate 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.
The CMX994A enables a significant reduction in power by allowing LO phase correction to be turned off. A further reduction is made possible by the facility to disable either the I or Q channel. The CMX994E expands on that by adding an enhanced performance mode that features improved intermodulation in the receive path mixers.
Operate 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.
Design Support Information
Q, Are the CMX994A and CMX994E devices pin compatible with the CMX994 in my digital radio?
A, Yes all three devices are pin and function compatible. However if the CMX994A or CMX994E are used in an existing CMX994 design, is is recommended that the new extended DC Offset register is utilised.
There are additional benefits in adopting the CMX994A and CMX994E including additional low power operating modes and enhanced mixer IM capability immunity, these are illustrated below.