Evaluation of Phase Measurement Error in Digital Oscilloscopes

In electrical and electronic circuit measurements, frequency characteristics of the gain and phase in measurement systems are important for accurate measurements. Oscilloscopes have a concern about phase measurement errors caused by the jitter of triggers and individual differences of each channel. This paper discusses a measurement method to reduce the measured phase error for the characterization of power electronics circuits and their peripheral components up to several tens of MHz operations with a digital oscilloscope. The difference in possible phase measurement errors induced by measurement settings of an oscilloscope is experimentally investigated. The settings are the sampling frequency, vertical scale, and averaging number on acquisition modes.