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Manual zz. In the form of a populated PCB, this flexible platform enables users, using a control interface, to configure and evaluate the CMX to various applications and frequency bands.
Access is provided to all CMX RF, baseband and control signals by either connector or test points. Test access points are available to accept common test equipments such as RF and baseband signal generators and spectrum analysers. All signal paths are matched by suitable components and the EvKit provides, on-board, two power amplifier devices, one at MHz default and one at MHz; support is also available for the connection and operation of a custom PA.
Also a custom C-BUS interface and control system can be used. Brief Description Preliminary Information Laboratory Equipment Power Supply Handling Precautions Static Protection Contents - Unpacking Quick Start Input Conditions Signal Lists Circuit Schematics and Board Layouts Detailed Description Hardware Description Power Amplifiers Local Oscillator LO IQ Baseband Inputs CMX Interface Manual DC Nulling Adjustments and Controls Software Description The Script Handler Tab Application Information Error Configuration Typical Performance of Closed Loop Configuration Closed Loop Operation Open Loop Operation Performance Specification Electrical Performance Absolute Maximum Ratings Operating Limits Operating Characteristics On board regulators are provided to generate all voltage rails used on the PCB 3.
The supply to the PA is directly connected to the PA: a voltage of 3. See also section 6. NOTE: Care should be exercised with the supplies, as they are not protected for reverse polarity. Handling Precautions Like most evaluation kits, this product is designed for use in office and laboratory environments. The following practices will help ensure its proper operation.
Partially damaged circuits can function erroneously, leading to misleading results. Observe ESD precautions at all times when handling this product. Contents - Unpacking Please ensure that you have received all of the items on the separate information sheet EK and notify CML within 7 working days if the delivery is incomplete. Approvals This product is not approved to any EMC or other regulatory standard. Users are advised to observe local statutory requirements, which may apply to this product and the radio frequency signals that may emanate from it.
EV Quick Start This section provides instructions for users who wish to experiment immediately with the evaluation kit.
A more complete description of the kit and its use appears later in this document. Setting-Up The following procedure is recommended: 1. Connect test leads as shown below in Figure 2.
The default frequency of operation for the EV is MHz. Power should be applied to the main supply 7. A connection should be made to J12 pin 15 to allow the PA control volts to be adjusted 6.
Power should be applied to the power amplifier supply connector 3. The board is now ready for operation. The CMX datasheet gives details of the registers and commands. The general control register should be configured such that the bias circuits, filter amplifiers, input amplifiers, error amplifiers, forward path and feedback path are all enabled. Bits 0 and 1 of the general control register should be in their normal operation state i.
A typical setting for the phase control register would be Typical setting for the forward and feedback path attenuator would be 0dB and 13dB respectively this configuration gives full output power at MHz. The frequency control register should be set for divide by 2 mode this means that a LO input has to be applied at twice the operating frequency.
To achieve the nominal output power from the PA a control voltage of 1. The output should be analysed to ensure loop phase is set correctly. The level of the carrier signal needs to be adjusted for a minimum by use of VR1 and VR2.
Connector Pin No. Nominal input level is dBm. See schematics and CMX datasheet for details. Leave unconnected. Not used. Default Measuremen t TP1 3. EV Circuit Schematics and Board Layouts For clarity, circuit schematics are available as separate high-resolution files. These can be obtained via the CML website.
State 2, when referring to schematic DWGB These changes have already been made to the Evaluation Kit. Operation at MHz to MHz.
Support for customer power amplifiers at different powers and frequencies over the full operating range of the CFBL IC. Interface to a PC for initial test and customer evaluation is available separately with suitable PC software that allows control of all device functions. Hardware Description 6. The gains are set in the baseband amplifier sections to suit the input drive levels in section 6. The error amplifier is configured with a loop filter optimised for operation with the on-board power amplifiers but can be configured with user values for any other requirements.
It is possible to access the up-converter output and the down-converter input so that customers can connect their own power amplifiers into the loop. The user can pull this pin low to reset the device or the software reset can be used. Component changes are required to make use of this option, see section 6. Gain control has been included which allows the power amplifiers to be connected to the CMX Ramping DAC or to an external variable voltage source.
A connector is provided to allow an external oscillator source to be injected at twice or four times the RF output frequency depending on the oscillator mode selected. The input can be differential or single ended. Adjusting the values around the CMX input amplifiers creates the required input configuration. They affect the DC level of at the input to the modulator so that the carrier can be nulled to a minimum manually. Automatic control has been implemented through the CMX interface.
On board regulators are provided to generate voltage rails used on the EV 3. The power supply to the PA is directly from a separate 3.
Adjustments and Controls The user has the ability to configure the EV for a number of different operational scenarios. The ES application allows the user to interact with the EV via an easy to use graphical interface. It consists of three tabs: each one representing a particular set of registers or a particular function of the CMX To select a tab simply click on the corresponding name in the row at the top of the program window.
Setting or clearing the check box associated with a bit of a register will cause that bit to be set or cleared when the register is next written to. In the case of the gain and phase control register slide bars have been used to allow easy control during operation.
CMX998 Transmitter. Datasheet pdf. Equivalent
Included are forward and feedback paths; local oscillator circuitry including loop phase control; an instability detector and uncommitted op-amps for input signal conditioning. Read More. Please ensure that you have downloaded the latest datasheet containing up-to-date information on product operation, technical specifications and packaging. The modulation accuracy of a CMX transmit is determined by the down-converter feedback path. A worst-case value of —30dB is guaranteed. Note that a different loop-filter might be required for the kHz and kHz channels.
CMX998 – Cartesian Feedback Loop Transmitter
No Preview Available! CML Microcircuits. Cartesian Feed-back. Loop Transmitter. A Cartesian Loop improves the efficiency and linearity of transmitters for non-constant envelope. Acting as.