Perform Frequency Response Analysis Easily

Introduction

A Bode plot is a graph of the frequency response analysis of a mechanical or electrical system, combining a magnitude plot and a phase plot. The frequency response measurement provides many performance indicators, such as the lifespan of a switching power supply, dynamic response, noise, output ripple, and interference immunity.

Designers can use these measurements to characterize the dynamic performance and reliability to ensure switching power supply design quality. Performing frequency response analysis manually with a traditional oscilloscope and function generator is time-consuming, with insufficient dynamic range test results. The industry needs easy-to-operate and visualized Bode plot measurement equipment.

Use Case Summary

With the development of wideband devices, the switching speed of switching power supplies is getting faster. Bode plot measurement is becoming a critical test for switching power supply design. It characterizes dynamic performance and reliability metrics and ensures switching power supply design quality. Using dedicated Bode plot analyzers or network analyzers may get erroneous results because users cannot judge whether there is a distortion to the waveform.

In contrast, oscilloscopes can display real-time waveforms to prevent the injection voltage, causing waveform distortion. In the power electronics industry, the utilization rate of oscilloscopes is much higher than a dedicated Bode plot analyzer. An oscilloscope with built-in Bode plot measurement can save time, protect the user’s investment, and improve equipment utilization through power supply test analysis software.

Solution Overview

The Keysight frequency response (Bode plot) measurement solution includes the Keysight Infiniium MXR- or EXR-Series oscilloscopes. Each platform has a built-in waveform generator as the signal source to realize the function of the frequency response test using Keysight D9010PWRA power supply test software. This solution breaks through the noise limitation of the broadband equipment through fast Fourier transform (FFT) operation. It also provides comparable test results and a dynamic range of the network analyzer. You can perform automatic frequency response analysis using the oscilloscope’s built-in waveform generator and automated in-scope control loop response (Bode plot) software as a sine wave input source.

Learn more at: D9110PWRA – Data Sheet

Summary

• Performing frequency response analysis manually with a traditional oscilloscope and function generator is a time-consuming process.

• The frequency response (Bode plot) measurement solution has completely changed the test process. The Infiniium MXR- or EXR-Series oscilloscopes are Bode plot measurement instruments that performs a control loop response measurement automatically.

• Side-by-side testing with a Keysight network analyzer shows that the gain and phase measurements of the Infiniium Series oscilloscope are accurate and reliable.

For more information: Frequency Response (Bode plot) Measurement