Diodes and Transistors

Abstract

In all basic circuits of the pulse DC/DC or DC/AC voltage converters, the switching elements are transistors (bipolar and unipolar) and diodes. In the analysis of a basic circuit, transistors and diodes have been considered as ideal switches (zero on-resistance, infinite off-resistance, and instantaneous transition from one state to the other). However, they are not ideal switches but have real parameters, in both the static and dynamic modes of operation. The influence of these parameters on the characteristics of pulse converters is considerable, particularly on the efficiency factor. For this reason, in this chapter, a description is given of the basic switching characteristics of transistors (bipolar and unipolar) and diodes. An analysis is presented of the modes of control of transistor switches and the optimum control circuits are given. The analysis is of a general character and applies to all pulse assemblies using diodes or transistors as switches.