Most industrial and consumer electronics are powered from a dc source whose voltage level is fixed in advance.
For examples, telecommunication electronics usually receive their input power from a 48V dc source and cellular phones operate with 3 V rechargeable batteries.
Meanwhile, circuits inside such equipment require several dc voltages that are different from the voltage level of the input source.
Accordingly, each equipment contains specially-engineered circuit blocks capable of changing the input voltage to another dc level, as required by the various internal circuits.

The process of changing the voltage level of a dc power source into another value is broadly referred to as the dc-to-dc power conversion.
The dc-to-dc power conversion is performed in many different ways, each with a distinctive circuit technique.
The most popular scheme is the dc-to-dc power conversion circuit employing the pulsewidth modulation (PWM) technique.
The dc-to-dc power conversion based on the PWM technique is called the PWM dc-to-dc power conversion. Circuitries designed for the PWM dc-to-dc power conversion are called PWM dc-to-dc converters

This book is primarily intended to be a textbook for undergraduate and first-year postgraduate students who are beginning to study power electronics focusing on the PWM dc-to-dc power conversion.
The book supplements existing textbooks with more dedicated treatments on the PWM dc-to-dc power conversion.
The book is also written as a reference book for engineers working in the area of modeling, analysis, and control of PWM dc-to-dc converters.