Why do we need multiple amplifier stages in electronic circuits?

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Discussion Overview

The discussion revolves around the necessity of multiple amplifier stages in electronic circuits, particularly in the context of amplifying small AC signals. Participants explore various reasons for using multiple stages, including gain, stability, distortion, and trade-offs in design.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the need for multiple amplifier stages, suggesting that a single RC transistor amplifier can achieve maximum swing with a collector voltage at half Vcc, and wonders if additional stages are only for increasing current.
  • Another participant notes that linearizing amplifier stages to reduce distortion requires negative feedback, which can decrease overall gain.
  • Concerns are raised about the risk of oscillation with too much gain in a single stage, suggesting that multiple stages can help maintain stability.
  • A participant discusses the Gain Bandwidth Product (GBP) and how it influences the choice between single and multiple amplifier stages based on desired gain and bandwidth.
  • Some participants argue that negative feedback can improve DC stability but may degrade dynamic stability, leading to a trade-off in design considerations.
  • There is mention of confusion regarding the terms "stability" and "feedback," with a participant emphasizing that negative feedback does not improve dynamic stability against oscillations.
  • Several participants express that the design of amplifiers often involves trade-offs between conflicting requirements, such as stability, bandwidth, and harmonic distortion.
  • One participant requests mathematical proof regarding the effects of negative feedback on stability, indicating a desire for deeper technical clarification.

Areas of Agreement / Disagreement

Participants express a range of views on the necessity and implications of multiple amplifier stages, with no clear consensus reached. Some agree on the importance of stability and trade-offs, while others emphasize different aspects of amplifier design.

Contextual Notes

Participants highlight the complexity of amplifier design, noting that various factors such as gain, stability, and feedback interact in nuanced ways, which may not be fully resolved in the discussion.

Who May Find This Useful

This discussion may be of interest to electronics students, engineers involved in circuit design, and hobbyists looking to understand the principles behind amplifier stages and their implications in electronic circuits.

  • #31
LvW, what makes you think your questions have more priority than anyone else? I don't believe you have asked me a direct question so it would be pretty hard for me to answer. I don't believe I ever said you are "most outright wrong". I have seen what I have seen and I know what I know. It would have been nice to resolve this with a simple admission from one side or the other that phase margin or something else is being considered by one side and not the other. What a waste this has turned into.
-
Edit: I believe milesyoung was the first to ask a question besides the original poster. Wouldn't it be logical that his question is answered first?
 
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  • #32
Averagesupernova - please, excuse me. As far as the statement "most outright wrong" is concerned, I have I have mixed milesyoung`s answer (post#25) with one of your answers. I am sorry for that.
Nevertheless, I do not like to continue this (slightly aggressive) "discussion" - and it does not help the OP at all.
As far as the technical aspects are concerned, I just have said everything I wanted to say.
Bye bye.
LvW
 
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  • #33
My excuses about the late respond. I was away for a bit and couldn't chat back. My thanks to all of you who answered to this thread. Thank you!
 
  • #34
handbags girls
 
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