Switched‐inductor dc–dc power supplies are pervasive in consumer electronics. This is because they deliver a large fraction of the power they draw with an output voltage that is largely independent of the load and the input. Keeping the output voltage steady this way is the responsibility of the feedback controller. This talk uses insight and intuition to show how pulse‐width‐modulated (PWM), hysteretic, and timed peak/valley loops switch the inductor, offset the voltage they control, and respond to load dumps and input variations. The presentation then shows how summing comparators operate and how they can contract, offset, and compensate these control loops (for reduced offset and stable operating conditions). Some of the topics discussed include negative feedback, frequency response, bandwidth, response time, sub‐harmonic oscillations, and voltage‐ and current‐mode control. While some of the concepts discussed can be found in literature, they are often abstract, algebraic, incomplete, and spread over several sources. This presentation, on the other hand, is concise, comprehensive, and full of insight. With this background and understanding, designing and implementing compact feedback controllers for switched‐inductor power supplies is more straightforward. This tutorial is intended for entry, intermediate, and advanced technologists in the field of power electronics.
