Basic Electronics Ninth Edition Grob Schultz ©2002 The McGraw-Hill Companies Basic Electronics Ninth Edition CHAPTER Transistor Amplifiers ©2003 The McGraw-Hill Companies Topics Covered in Chapter 30 Circuit Configurations Class A, B,
Download ReportTranscript Basic Electronics Ninth Edition Grob Schultz ©2002 The McGraw-Hill Companies Basic Electronics Ninth Edition CHAPTER Transistor Amplifiers ©2003 The McGraw-Hill Companies Topics Covered in Chapter 30 Circuit Configurations Class A, B,
Basic Electronics Ninth Edition Grob Schultz ©2002 The McGraw-Hill Companies Basic Electronics Ninth Edition CHAPTER 30 Transistor Amplifiers ©2003 The McGraw-Hill Companies Topics Covered in Chapter 30 Circuit Configurations Class A, B, or C Operation Analysis of Common-Emitter (CE) Amplifier Collector Characteristic Curves Letter Symbols for Transistors Topics Covered in Chapter 30 (continued) FET Amplifiers Types of Distortion Negative Feedback Troubleshooting Amplifier Circuits Types of Amplifiers for Junction Transistors • Common-Emitter (CE) phase inversion voltage, current, and power gain • Common-Collector (CC) no phase inversion no voltage gain, but has current and power gain • Common-Base (CB) no phase inversion no current gain, but has voltage and power gain Common-Emitter Amplifier R1 C1 RL C2 R2 RE Common-Collector Amplifier R1 C1 C2 R2 RE Common-Base Amplifier R1 RL C2 C3 R2 RE C1 Classes of Operation • Class A 360° conduction least distortion, least efficient • Class B 180° conduction • Class C less than 180° conduction most distortion, most efficient Class A Operation 360° conduction IC 0 Time Collector Current Waveform Class B Operation 180° conduction IC 0 Time Collector Current Waveform Class C Operation 90° conduction IC 0 Time Collector Current Waveform Measuring Transistor Characteristics IC VCE IB Collector Family of Characteristic Curves 100 mA 14 12 10 IC in mA 8 6 4 2 80 mA 60 mA 40 mA 20 mA 0 2 4 6 8 10 12 14 16 18 VCE in Volts 0 mA Gain of Junction Transistors • Beta (b) Defined as the ratio IC/IB Determines the current gain of CE amplifiers Typical values are 10 to 300 • Alpha (a) Defined as the ratio IC/IE Values less than 1, typically 0.98 or 0.99 Transistor Gain 10 mA IC b= IC IB IC = 10mA = 100 100mA 10mA a= = = 0.99 I E 10.1mA 100 mA IB 10.1 mA IE Types of FET Amplifiers • Common-Source Corresponds to a CE circuit for a junction transistor: signal inversion, voltage gain and power gain. • Common-Drain Corresponds to a CC circuit for a junction transistor: no signal inversion, no voltage gain, has power gain. • Common-Gate Corresponds to a CB circuit for a junction transistor: no signal inversion, voltage gain and power gain. Common-Source Amplifier RL D G C1 R1 C2 S RS Common-Drain Amplifier D G C1 S R1 RS C2 Common-Gate Amplifier RL D G C3 R1 C2 S RS C1