As a state-of-the-art design for an integrated CFBL, the CMX improves the . connecting circuitry, details of which are given in the product datasheet. The CMX is an integrated solution for a Cartesian Feedback Loop based linear transmitter. Acting as a direct conversion quadrature mixer from I and Q to RF. CMX datasheet, CMX circuit, CMX data sheet: CMLMICRO – The Product Data Amendment series of documents,alldatasheet, datasheet, Datasheet.

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If you continue to use this site we will assume that you are happy with it. For clarification, the relevant change is: There is nothing specific to be aware of when powering the EV up for the first time, adtasheet it is very important to ensure that a 50ohm load is attached to J9 before enabling the power amplifier.

It is important to read the included readme.

A simple guide to help users get started evaluating the DE The darasheet detector is designed to detect minor phase variations and resultant instability following initial phase correction. Technical Portal No additional information available. The degradation is due to the gain-expansion caused by the linearity correction for the non-ideal PA.

The CMX instability detector cannot detect lead or lag error as it works on a simple baseband signal. We can tailor an existing product to your unique requirements Learn more Contact us. The measurements include the effects of the non-ideal PA that is corrected by the Cartesian loop. Both Single Ended and Differential modes are shown.

The CMX includes gain adjustment to make threshold setting easier.


Note that a different loop-filter might be required for the kHz and kHz channels. I am looking to develop a high quality non-constant envelope transmitter and am looking to improve the linearity cmx99 my current design. This means a common shift is applied to DC offset correction signal and modulator reference. This effect can be avoided by using BVREF to bias datazheet input signal rather than using a resistor network tied to 3.

EV high resolution schematics and component overlay. What can I do to ensure a stable carrier leakage when I enable the RF detector?

CMX998 – Cartesian Feedback Loop Transmitter

We use cookies to ensure that we give you the best experience on our website. The data will appear in the grayed-out data box. A simple guide to help users get started evaluating the EV If a design supports dynamic loop phase calibration then an instability detector event normally triggers loop re-calibration. The output power will decrease once the PA is powered down, and this results in a lower signal level fed datashdet into the CMX The instability detector comprises a high-pass filter followed by a peak-detector circuit and this combination indicates the presence of this high frequency energy.

Are there any particular aspects of power-up or down sequence of the EV that I should be aware of? These scripts require the following evaluation boards: If the loop is set up degrees out of phase the loop will oscillate and will generally produce a maximum level carrier.

This App Dwtasheet discusses these issues using the DE in a worked example. The results from this improved configuration are also shown in Table 1 and although a small degradation is still observed the carrier leakage is still dBc, which is considered more than adequate for most applications. This process will continue as the PA output ramps down, with the up converter output and PA input signal level continuously increasing.


Such effects are unlikely to cause a phase shift as large as degrees.

CMX Datasheet(PDF) – CML Microcircuits

Do you have any recommended signal-levels that will allow me to see the CMX at its best? This can over-drive the PA which may over-current and fail.

Datasheets CMX Datasheet rev If the loop becomes unstable due to phase inaccuracies the feedback loop will tend to spill energy out-of band. There is a preferred method of cmc998 down the EV to also avoid damage to the power amplifier PA. This issue can be greatly reduced if the alternative configuration for applying a bias voltage to the input signal is used, as documented in EV Datasheet version 5 and above.

The instability detector found on the CMX is a relatively simple mechanism that measures the level of out-of band energy of the feedback loop. If instability is detected then normal procedure is to power down the transmitter. There are three CMX internal registers that are key for this discussion: Using a Cartesian transmitter in TDMA dstasheet can be challenging when supporting multiple modulation formats.

These scripts can be easily modified to support other Block Types. Three scripts for evaluating performance of a multi-mode modem using the DE