UG-435 Datasheet, PDF (11/20 Pages) Analog Devices – Evaluation Board for the ADF4351 Fractional-N PLL Frequency Synthesizer

Evaluation Board User Guide
EVALUATION AND TEST
To evaluate and test the performance of the ADF4351, use the
following procedure:
1. Install ADF435x software.
2. Connect the evaluation board to a PC using the supplied
USB cable. Follow the hardware driver installation
procedure that appears.
3. Connect spectrum analyzer to Connector RFOUTA+.
4. Connect 50 Ω termination to RFOUTA−.
5. Run the ADF435x software.
6. Select the USB board and the ADF4351 device in the
Select Device and Connection tab of the software front
panel window.
7. In the software window, click Write All Registers. See
Figure 19 for the suggested setup.
8. Measure the output spectrum. Figure 20 shows a
phase noise plot at 2.5 GHz output.
9. Different combinations of reference and PFD frequency
may require changes to the REFIN stage or PFD frequency.
Low output frequencies may require different output stage
elements.
UG-435
Figure 20. Spectrum Analyzer Display
REFERENCE (OPTIONAL)
REFERENCE IN/
REFERENCE OUT
USB
TCXO
POWER
USB CRYSTAL
LED
PC
AND PROCESSOR
LOCK DETECT LED
EXTERNAL DC
SUPPLY
EXTERNAL DC
GND
EXTERNAL
POWER
SWITCH
USB
POWER
SWITCH
PLL
POWER
LED
ADF4351
LOOP
FILTER
SPECTRUM
ANALYZER
50Ω
TERMINATION
Figure 21. Typical Evaluation Setup
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