A frequency response analyser is a piece of test equipment designed to inject a sinewave into a circuit, and measure the frequency response of the circuit at multiple test points in order to generate a gain and phase response. This application provides Frequency Response Analysis (FRA) capabilities for the PicoScope instruments from Pico Technology. The FRA uses a common technique of frequency sweeping (in this case stepping), and DFT extraction. The main output is a Bode plot of gain in dB and phase in degrees. FRA has several use cases, some of which may be limited by the capabilities of the scope. Some examples include:
  • Filter characterization
  • Feedback loop analysis, to characterize control system stability and responsiveness
  • A subset of feedback loop analysis includes power supply stability analysis
  • General impedance measurements
The user supplies basic inputs such as channel settings, input signal amplitude, and sweep range. Once the FRA is started, the execution is automated, including all necessary auto-ranging. Once the analysis is complete, a plot of the data is displayed. This data can be exported into image files or raw data. The following is an example screenshot from a FRA execution for a 1 kHz RC highpass filter. KnowledgeBasePD_500 Click here for full details.