Broadcom
ACPL-C740-EvalKit-UG100
4
ACPL-C740 Evaluation Kit Board
User Guide
Isolated Sigma-Delta Modulator
Application GUI
The application GUI has three displays: two showing the signal in the time domain and frequency domain, and a third
showing SNR and SNDR historical plots. The time domain signal can be displayed in terms of ADC count or voltage level
(mV) by checking the Display (mV).
Figure 3: Application GUI Example
To the right of the displays, real-time minimum, maximum, and average signal levels are shown in the time domain in terms
of either mV or ADC count. SNR, SNDR, 2nd harmonic, and 3rd harmonic levels are displayed in the frequency domain.
1. Click
Start
to begin capturing the input signal. The configured board frequency is captured under the Frequency box and
the type of sigma-delta modulator in terms of input range and output signal type displays in the Board/Product.
2. Save the signal, FFT, and SNR/SNDR history data into text files that are readable and compatible to Microsoft Excel by
selecting the Datalog (signal, fft, and snr/sndr history) box. The snr.txt, signal.txt, and fft.txt files are stored in the same
file directory as the application GUI.
