8-1 McGraw-Hill Copyright © 2001 by the McGraw-Hill Companies, Inc. All rights reserved. Chapter Eight Output Stages and Power Amplifiers.

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

8-1Chapter Eight

Output Stages

and

Power Amplifiers

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

8-2Figure 8.1Typical dc beta characteristics (hFE versus lc) for 2N3055

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8-3Figure 8.3The safe operating area of a bipolar transistor plotted on: (a) linear scales and (b) logarithmic scales

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8-4Figure 8.7Typical characteristics for high-power MOSFETs: (a) transconductance versus drain current; (b) transfer characteristics

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

8-5Figure 8.8(a) Cross section of a VMOS device; (b) cross section of DMOS device; (c) HEXFET structure

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8-6Figure 8.15Collector current versus time characteristics: (a) class-A amplifier, (b) class-B amplifier, (c) class-AB amplifier, and (d) class-C amplifier

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8-7Figure 8.16(a) Common-emitter amplifier, (b) dc load line, and (c) instantaneous power dissipation versus time in the transistor

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8-8Figure 8.20Crossover distortion of basic complementary push-pull output stage

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8-9Figure 8.23Bipolar class-AB output stage

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8-10Figure 8.24Characteristics of a class-AB output stage: (a) voltage transfer curve,(b) sinusoidal input signal, (c) collector currents, and (d) output current

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8-11Figure 8.28(a) Transformer-coupled common-emitter amplifier and (b) dc and ac load lines

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8-12Figure 8.30Class-AB output stage with quiescent bias established by diodes

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8-13Figure 8.31Class-AB output stage with VBE multiplier bias circuit