EE100B-p05 feedback Amplifier in electronics.ppt
Download as PPT, PDF0 likes10 views
The document discusses the general structure and function of feedback amplifiers, emphasizing signal-flow diagrams and the application of negative feedback to improve performance metrics such as signal-to-noise ratio and reduction of nonlinear distortion. It provides detailed descriptions of various feedback configurations, including voltage and current mixing solutions, with accompanying figures illustrating their characteristics and practical implementations. Additionally, it includes derivation steps for specific circuits and rules for analyzing feedback systems.
EE100B-p05 feedback Amplifier in electronics.ppt
- 1. 1 Figure 8.1 General structure of the feedback amplifier. This is a signal-flow diagram, and the quantities x represent either voltage or current signals. The General Feedback Structure Feedback Feedback 1 o f s x A A x A
- 2. 2 Gain Desensitivity 2 (1 ) f dA dA A 1 1 f f dA dA A A A 1 f A
- 3. 3 Figure 8.2 Illustrating the application of negative feedback to improve the signal-to-noise ratio in amplifiers. Noise Reduction 1 2 1 1 2 1 2 1 1 o s n A A A V V V A A A A
- 4. 4 Figure 8.3 Illustrating the application of negative feedback to reduce the nonlinear distortion in amplifiers. Curve (a) shows the amplifier transfer characteristic without feedback. Curve (b) shows the characteristic with negative feedback ( 0.01) applied. Reduction in Nonlinear Distortion
- 5. 5 Voltage-Mixing Voltage-Sampling (Series–Shunt) Feedback voltage amplifier
- 6. 6 Current-Mixing Current-Sampling (Shunt–Series) Feedback current amplifier let Is increase …
- 7. 7 Voltage-Mixing Current-Sampling (Series–Series) Feedback transconductance amplifier
- 8. 8 Current-Mixing Voltage-Sampling (Shunt–Shunt) Feedback transresistance amplifier
- 9. 9 Figure 8.8 The series–shunt feedback amplifier: (a) ideal structure and (b) equivalent circuit. The Series–Shunt Feedback Amplifier
- 10. 10 Figure 8.10 Derivation of the A circuit and circuit for the series–shunt feedback amplifier. (a) Block diagram of a practical series–shunt feedback amplifier. (b) The circuit in (a) with the feedback network represented by its h parameters. The Practical Situation
- 11. 11 Figure 8.11 Summary of the rules for finding the A circuit and for the voltage-mixing voltage-sampling case of Fig. 8.10(a).
- 12. 12 Figure 8.12 Circuits for Example 8.1. Example 8.1