Cirrus Logic CapturePlus II - Manual (Page 24)

CapturePlus II
24 DS789UM2
APPENDIX A. TESTING THE CIRRUS LOGIC CDB556x/7x/8x EVALUATION BOARD
The following sections describe several basic tests performed to establish basic system functionality and
baseline noise and distortion levels.
A.1 Baseline Testing for Noise & Distortion
A.1.1 Baseline Noise & Distortion Test - Non-Averaged FFT
Connect the evaluation board power inputs to a bench supply having the appropriate voltages.
Connect the evaluation board’s analog input(s) to circuit ground (in most cases, the 50
Ω termination re-
sistors on the input will be adequate).
Select the Frequency Domain window (selected by clicking on the Frequency Domain tab at the top of the
screen). Activate the Grounded Input FFT and Log Freq Scale buttons. Select the Window Type to be
Crystal 7-Term.