This textbook uses design insight, real-life examples, illustrative figures, easy-to-follow equations, and simple SPICE code to show how semiconductor devices (diodes, bipolar-junction transistors (BJTs), and metal-oxide-semiconductor (MOS) field-effect transistors (FETs) ) work independently and collectively in switched-inductor power supplies; how these power supplies transfer power, consume power, and react and respond across frequency; how feedback loops switch, control, and stabilize them; and how the building blocks that comprise them are implemented and designed. This book is focused and complete, with a holistic approach and perspective on power IC design that extends from semiconductor devices to fully-closed feedback systems. Readers will develop the insight needed to interpret, assess, and design switched inductor power ICs, which almost all electronic systems need, yet no other book addresses this way.