Evaluation Kit for CMX990
EV9900A
6.2.2 External Local Oscillator
To evaluate the performance of the CMX990 it is recommended that a low noise external
oscillator be used for the main LO. This is particularly important when performing blocking and
adjacent channel tests. An external main LO can be supplied via J10. The following changes are
recommended:
•
•
Remove R78, R81, R164 and R200 (supplies to on-board VCO’s).
Ensure C98 (1nF) and R149 (18Ω) are fitted.
6.2.3 Intermediate Signal Connections
The EV9900A allows a user to connect signals at various points in the signal path of the IC.
Details can be found on the schematic and in the list of connectors. Users can choose
appropriate matching and configurations to suit their requirements. Note that just connecting test
equipment to the ports may not give the expected results – correct RF matching arrangements
are required.
6.3
6.4
Firmware Description
The EV9900A has no embedded firmware.
Software Description
CML products DE9901 and EV9902 (not included) can be used with the EV9900A and include
related software.
6.5
Application Information
6.5.1 TX Loop Operating Power Levels
The range of input powers to the feedback port (TxFB) of the offset loop is designed to allow
operation over an 65dB range (approximately +8 to –57dBm). This is to permit the loop to lock
prior to commencing power ramping.
6.6
Evaluation Tests
The EV9900A is intended to allow evaluation of CMX990 RF and baseband performance. The
following is a list of typical tests from radio modem standards (e.g. EN300113). Some guidance
notes on likely EV9900A performance at 410-430MHz are provided.
Frequency Error
Compliant, based on a selected 14.4MHz VCTCXO.
© 2007 CML Microsystems Plc
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UM9900A/3
CMLMICRO [ CML MICROCIRCUITS ]
