Fundamentals of Oscilloscope Measurements in Automated Test Equipment (ATE)

Measurements performed by instrumentation comprise an essential part of electronic testing by automated test equipment (ATE). As military and commercial electronics become increasingly complex, more sophisticated instrumentation is required to validate performance and diagnose failures. Advanced measurement capabilities of modern instrumentation make them extremely powerful, but also add significant complexity for the user. As an example, the digital storage oscilloscope, an instrument found in most ATE systems, has become a very powerful test and diagnostic tool. Unfortunately, many oscilloscope users take advantage of only a small fraction of the powerful features available to them. Waveform measurements are a fundamental oscilloscope feature that, if not used properly, can return inaccurate or misleading results. Selecting the right measurement from a catalog of possibilities and accurately interpreting the results can cause confusion and mistakes. This paper describes the subtle differences between many standard measurements, discusses measurement limitations due to accuracy and resolution, and provides typical applications to illustrate measurement usage. Ultimately, this information should help the user avoid common pitfalls in applying oscilloscope measurements within ATE.