Unformatted text preview: still used today. Our
objective is to present enough detail about the BJT to enable us to apply
the techniques developed in this chapter to analyze dc transistor circuits.
There are two types of BJTs: npn and pnp, with their circuit symbols
as shown in Fig. 3.38. Each type has three terminals, designated as emitter (E), base (B), and collector (C). For the npn transistor, the currents and | e-Text Main Menu | Textbook Table of Contents | Problem Solving Workbook Contents CHAPTER 3 Methods of Analysis 103
Collector C n
p Base B n E Emitter
Collector C p Figure 3.37 B n
Various types of transistors.
(Courtesy of Tech America.) E Emitter voltages of the transistor are speciﬁed as in Fig. 3.39. Applying KCL to
Fig. 3.39(a) gives
IE = IB + IC (3.27) (b) Figure 3.38 Two types of BJTs and
their circuit symbols: (a) npn, (b) pnp. where IE , IC , and IB are emitter, collector, and base currents, respectively.
Similarly, applying KVL to Fig. 3.39(b) gives
VCE + VEB + VBC = 0 C
IC (3.28) IB wh...
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This note was uploaded on 07/16/2012 for the course KA KA 2000 taught by Professor Bkav during the Spring '12 term at Cambridge.
- Spring '12