Learn the basics of ADC testing

Martin Rowe, Senior Technical Editor -- Test & Measurement World, 9/1/2006

In our June 2006 cover story, “The world is still analog,” I described how engineers at Analog Devices use evaluation boards to characterize high-speed analog-to-digital converters (ADCs) (Ref. 1). To learn more about the 17 AC tests and eight DC tests that the engineers perform on ADCs, you can turn to a recently published application note, “Understanding High Speed ADC Testing and Evaluation” (Ref. 2).

The figure shows a typical test setup for many of those measurements. If you use digitizing measurement equipment such as oscilloscopes or data-acquisition systems, this note will help you understand ADC specifications. If you design ADCs into embedded systems, you’ll benefit from the explanations of how to evaluate an ADC.

A typical characterization setup consists of signal and clock sources, a filter, a power supply, an evaluation board, and a data-capture board. Courtesy of Analog Devices.

The authors discuss how to set up tests and how to use characterization software that you can download. The software performs FFTs and measures signal-to-noise ratio, signal-to-noise and distortion, spurious-free dynamic range, and other parameters. From the app note, you’ll learn which signal sources to use and when to apply low-pass filters and bandpass filters to your test setup.