CML’s CMX994 is a 100Mhz~-600MHz direct conversion receiver that integrates a wideband LNA with high dynamic range I/Q demodulator control gain. The receiver baseband part includes amplifiers and precision baseband filters, integer-N PLL and VCO negative. The resistive amplifier produces a local oscillation (LO), operates at 3.3V, and is mainly used in analog/digital multimode radios, SDRs, data telemetry modems, satellite communications, Cartesian feedback loop transmitters, broadband data, and more.

The device operates from a single 3.3V supply, has a temperature range of -40°C to +85°C, and is available in a small 40-pin VQFN (Q4) package.

Figure 1 CMX994 block diagram

Figure 2 Typical application block diagram of CMX994

Main features of CMX994

• RX direct conversion receiver

– Direct conversion eliminates image reactions

– LNA gain control

–100MHz~600MHz I/Q demodulation

– Precision filter band, wide setting and local oscillator 1:2:4 bandwidth mode

– LO Synthesizer

– Oscillator Negative Resistance Amplifier

• LO split into 2, 4 or 6 modes

– TX LO output

• 3.3V low power operation

• Small 40-pin VQFN package

• Low power mode

CMX994 application

• Analog/Digital Multimode Radio

• Software Defined Radio (SDR)

• Data telemetry modem

•Satellite Communications

• Constant envelope linear receive modulation

• The receive function is compatible with CMX998

• Cartesian feedback loop transmitter

• Narrowband: eg 25kHz, 12.5kHz, 6.25kHz

• Broadband data

EV9942 Evaluation Board

The EV9942 enables the user to review all aspects of the CMX994 integrated circuit, enabling a high performance direct conversion receiver. The evaluation board also includes additional circuitry (which can be used to evaluate system performance) and a fractional-N PLL, as well as a high-frequency VCO.

All CMX994 RF, baseband and control signals are accessible through connectors or test points.

The EV9942 also features test access points to access common test equipment such as RF and baseband signal generators and spectrum analyzers. All signal paths are matched to the appropriate components. The overall frequency range of this evaluation board is RF frequencies, 100MHz~600MHz, with default operation at 448MHz.

The CMX994 is controlled via its C-BUS serial interface. The interface card of the PE0002 can be used alone to provide support for the PC-based control of the EV9942.

Figure 3 EV9942 evaluation board block diagram

EV9942 Evaluation Board Key Features

• CMX994 evaluation receiver

– low noise amplifier

– I/Q output

– optional filter

• Send LO output

• CMX994 integer-N PLL

• External fractional-N PLL interface

• 19.2MHz VCTCXO

• Flexible external VCO

• On-board voltage regulator

• PC control interface

• PE0601, EV9810 interface

• or EV9100 evaluation kit

• 448MHz default operation

• 100MHz~600MHz evaluation

EV9942 Evaluation Board Features

• Demonstration of a linear direct conversion receiver from RF input

Input to output, I/Q format, including:

– LNA gain control

– I/Q mixer

– First baseband filter

– First baseband amplifier

– Second baseband filter

– Second baseband amplifier

• VCO integer-N PLL and divider

• TX LO output.

• Operates from 100MHz to 600MHz

(448MHz=default configuration)

• 19.2MHz VCTCXO

• On-board linear regulators for all necessary power rails

In conclusion, the EV9942 enables users to create experiments to review all aspects of the CMX994 device. EV9942 allows user modification to support user detailed investigation for specific and different applications. The evaluation platform also includes additional circuits that can be used to evaluate the performance of the system, such as fractional-N PLLs (U8) and high frequency VCOs (TR2/TR3).

For details, see:

http://solution.eccn.com/solution_2012011610213643.htm

GEC