Confused with Omp Amplifier Problem - Part B Solution

  • Thread starter Thread starter Saeed.z
  • Start date Start date
  • Tags Tags
    Amplifier
Click For Summary

Discussion Overview

The discussion revolves around a specific problem related to operational amplifiers (opamps), particularly focusing on part B of the problem. Participants are trying to clarify the meaning of the saturation voltage (Vsat) in the context of the circuit presented, as well as the configuration and behavior of the opamps involved.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants express confusion regarding whether Vsat refers to the right amplifier or the entire circuit.
  • One participant questions the role of the second opamp and its configuration, seeking to understand its output in relation to its input.
  • Another participant states that the second stage is not an inverting stage, contrary to an earlier claim, and emphasizes that the first stage is inverting.
  • There is a discussion about the saturation output voltage of opamps, with one participant noting that it is common for the saturation voltage to be less than the power rails, explaining why Vsat is listed as +/-12V instead of +/-15V.
  • Participants are questioning the assumptions made in the problem, particularly regarding the value of Vsat.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the interpretation of Vsat or the configuration of the second opamp, indicating that multiple competing views remain. The discussion is characterized by uncertainty and differing interpretations of the problem.

Contextual Notes

There are unresolved questions regarding the assumptions made about the opamp configurations and the saturation voltages, which may depend on specific definitions or characteristics of the opamps being discussed.

Saeed.z
Messages
28
Reaction score
1
i am confused with this problem , part b :

http://img85.imageshack.us/img85/1736/ampe.png

my question is : Does Vsat reffer to the right amp or the whole circuit ? or something wrong with this problem ? thanks :)
 
Last edited by a moderator:
Physics news on Phys.org
Saeed.z said:
i am confused with this problem , part b :

http://img85.imageshack.us/img85/1736/ampe.png

my question is : Does Vsat reffer to the right amp or the whole circuit ? or something wrong with this problem ? thanks :)

I don't think there is anything wrong with the problem.

What is that 2nd opamp doing? What is the name for the configuration it is in? What is its output in relation to its input? Does that help you answer your question about which stage saturates first?
 
Last edited by a moderator:
berkeman said:
I don't think there is anything wrong with the problem.

What is that 2nd opamp doing? What is the name for the configuration it is in? What is its output in relation to its input? Does that help you answer your question about which stage saturates first?

it inverts the left hand amp ,, ( the inverting amp ) . Vo = -12 Vs .

my question was : part b says that " assume Vsat =
gif.gif
12 " . Why not
gif.gif
15 ? thanks
 
Saeed.z said:
it inverts the left hand amp ,, ( the inverting amp ) . Vo = -12 Vs .

my question was : part b says that " assume Vsat =
gif.gif
12 " . Why not
gif.gif
15 ? thanks

No, the 2nd stage is not an inverting stage. The first stage is inverting, but the second is not.

The saturation output voltage of most opamps is less than the power rails, so that's why the Vsat is listed as +/-12V when the rails are at +/-15V. You can get more expensive opamps that have close to rail-to-rail outputs, but the voltages given in this problem are common for general opamps.
 

Similar threads

  • · Replies 8 ·
Replies
8
Views
2K
Replies
1
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
7K
  • · Replies 59 ·
2
Replies
59
Views
5K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 17 ·
Replies
17
Views
3K