Conventional differential probes often fail to provide a good representation of the actual signal due to limitations in their common mode rejection ratio, derating over frequency, frequency response, and the probe’s long input leads. These limitations are even more pronounced when testing on power devices with fast switching rates and even
nominal common mode voltage.
This article examines these sources of measurement error and looks at how an isolated solution such as the Tektronix IsoVu measurement system can overcome these limitations.