March 14, 2012 -- Switch-mode power supplies are used in most electronic systems. Especially in applications where linear voltage regulators were used previously, they offer the advantage of higher power efficiency and reduced thermal impact. However, evaluating a switch-mode power supply circuit in the lab requires some special knowledge, techniques, and set-up.

Although measuring output-ripple voltage, conversion efficiency, inductor current and loop stability seem straightforward, not applying the correct procedures will yield useless measurement results. This article introduces some of the most important procedures.

By Frederik Dostal. (Dostal is with Analog Devices, Inc.)