4-1 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Chapter Four Basic BJT Amplifiers

4-2 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.2 (a) Bipolar transistor inverter circuit; (b) inverter transfer characteristics

4-3 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.4 Common-emitter transistor characteristics, dc load line, and sinusoidal variation in base current, collector current, and collector-emitter voltage

4-4 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.5 Base current versus base-emitter voltage characteristic with superimposed sinusoidal signals

4-5 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.8 A simplified small-signal hybrid-  equivalent circuit for the npn transistor

4-6 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved.

4-7 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.13 Expanded small-signal model of the BJT, including the Early effect, for the case when the circuit contains the (a) transconductance and (b) the current gain parameters

4-8 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.22a Basic data sheet for the 2N2222 bipolar transistor

4-9 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.22b

4-10 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.28 A bipolar circuit with an emitter resistor, a voltage-divider biasing circuit, and a coupling capacitor

4-11 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.29 The small-signal equivalent circuit with an emitter resistor

4-12 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.44 Emitter-follower circuit

4-13 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.45 Small-signal equivalent circuit of the emitter-follower

4-14 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.53 Basic common-base circuit

4-15 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Figure 4.54 (a) Simplified hybrid-  model of the npn transistor and (b) small-signal equivalent circuit of the common-base circuit