1 Overview
There are many types of probes, among which high-voltage differential probes are widely used in switching power supply applications. However, many engineers do not have a deep understanding of differential probes. There are also many differential probe manufacturers on the market, and their performance indicators vary, and even vary greatly, resulting in different measured waveforms, and engineers cannot see the correct waveform. This article will mainly explain what is a differential signal, the measurement of differential signals, the main indicators of high-voltage differential probes, advantages and disadvantages, and related usage tips, as well as the typical applications of high-voltage differential probes in switching power supplies.
2. What is differential signaling?
Before explaining differential probes, let's first understand differential signals. Differential signals are signals that reference each other, not the ground. For example, the voltage signal in the upper and lower switches (Q1, Q2) of the half-bridge in the switching power supply in Figure 1; the voltage signal in the multi-phase power system in Figure 2, the above signals are essentially "floating" above the ground.