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November 5 2007. 1. Schedule. Due Friday, Nov 9 13.4,13.14,13.23,13.27Due Friday Nov. 1614.8,14.11,14.27,14.37Review Nov. 26Quiz 3: Nov 30Project Presentation Dec 3 and Dec 7. November 5 2007. 2. Introduction. Low output resistance to deliver power w/o loss, ie. efficiencyLinearity, ie. t
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1. November 5 2007 0 Output Stages and Power Amplifiers Chapter 14
Classification of Output Stages
Class A,B & AB
Biasing AB
Power BJT
2. November 5 2007 1 Schedule Due Friday, Nov 9
13.4,13.14,13.23,13.27
Due Friday Nov. 16
14.8,14.11,14.27,14.37
Review Nov. 26
Quiz 3: Nov 30
Project Presentation Dec 3 and Dec 7
3. November 5 2007 2 Introduction Low output resistance to deliver power w/o loss, ie. efficiency
Linearity, ie. total harmonic distortion criteria
Junction temperature and high power BJT
Waveform shape?
4. November 5 2007 3 Class AOutput Stage Collector current waveform
5. November 5 2007 4 Transfer Characteristic of Class A Emitter follower Q1 biased with constant current I supplied by Q2
6. November 5 2007 5 Transfer characteristic of the emitter follower
7. November 5 2007 6 Waveforms from Class A
8. November 5 2007 7 Class B Conducts only half of the cycle
9. November 5 2007 8 Power Dissipation Maximum instantaneous power in Q1 is VCCI.
Emitter follower dissipated most power when vO = 0.
If RL=0, short circuit, protection?
Power conversion efficiency:
10. November 5 2007 9 Power Efficiency Class B
11. November 5 2007 10 Linearity Transfer characteristic for the class B output stage
12. November 5 2007 11
13. November 5 2007 12 Opamp Implementation
14. November 5 2007 13 Class B Single Power Supply
15. November 5 2007 14 Class AB Conduction more than half cycle
16. November 5 2007 15 Class AB Conduction more than half cycle
17. November 5 2007 16 Transfer Function Class AB
18. November 5 2007 17 Determining Output ImpedanceClass AB
19. November 5 2007 18 Class AB using Diodes
20. November 5 2007 19 Class AB using V_BE multiplier
21. November 5 2007 20 Class AB with V_be multip+pot.
22. November 5 2007 21 Used in Radio frequency applications (mobile phones, radio and TV) Class C