Switching regulators are increasing in popularity because they offer the advantages of higher power conversion efficiency and increased design flexibility (multiple output voltages of different polarities can be generated from a single input voltage).
This paper will detail the operating principles of the four most commonly used switching converter types:
Buckused to reduce a DC voltage to a lower DC voltage.
Boostprovides an output voltage that is higher than the input.
Buck-Boost (invert)an output voltage that is generated opposite in polarity to the input.
Flybackan output voltage that is less than or greater than the input can be generated, as well as multiple outputs.
Also, some multiple-transistor converter topologies will be presented:
Push-PullA two-transistor converter that is especially efficient at low input voltages.
Half-BridgeA two-transistor converter used in many offline applications.
Full-BridgeA four-transistor converter (usually used in offline designs) that can generate the highest output power of all the types listed.
Application information will be provided along with circuit examples that illustrate some applications of Buck, Boost, and Flyback regulators.