# Finding R for Ideal Op Amp to Avoid Saturation

• weedannycool
In summary, the conversation is about determining the range of resistance values for which an op amp does not saturate, given that it saturates at +/-14V and assuming it is ideal. The homework equations include V-=V+ and the attempt at a solution involves a voltage divider for V+ and a variable voltage divider for V-. The goal is to find the range of R values that will prevent the output from reaching +/-14V.
weedannycool

## Homework Statement

if the op amp satuates at +-14v, determne te the range of values of risitance R for which the op amp does not saturate. Assume the op amp is idal

V-=V+

## The Attempt at a Solution

this is wa i have so far: (2-5/3)+(2-+14/R). not sure if it is right? COuld some1 help me solve this ?

#### Attachments

• omp.jpg
6.8 KB · Views: 352
The risistor after the power sorce is a mistake so ignore. thanks

weedannycool said:

## Homework Statement

if the op amp satuates at +-14v, determne te the range of values of risitance R for which the op amp does not saturate. Assume the op amp is idal

V-=V+

## The Attempt at a Solution

this is wa i have so far: (2-5/3)+(2-+14/R). not sure if it is right? COuld some1 help me solve this ?

Welcome to the PF. Could you please be a little more clear about how you derived the start of an equation above? There is at least one "-+" typo in it as well. And an equation needs to have an "=" sign in it, remember.

You have a voltage divider making the voltage at the V+ input, and a variable voltage divider connected to the V- pin. And you correctly state that V+ = V- for an ideal opamp. So that should help you calculate the range of R values that keep the output from reaching +/-14V.

## 1. What is the ideal value of R for an op amp to avoid saturation?

The ideal value of R for an op amp to avoid saturation depends on the specific characteristics of the op amp being used. Generally, a lower value of R will help to avoid saturation, but it is important to consult the datasheet of the op amp to determine the recommended value for your specific application.

## 2. How does R affect the saturation of an op amp?

R, or the feedback resistor, plays a critical role in the stability and performance of an op amp. As the feedback resistor value increases, the gain of the op amp decreases, making it less likely to reach saturation. However, if R is too high, the op amp may become unstable and exhibit oscillations or other undesirable behavior.

## 3. Can I use a larger or smaller value of R to avoid saturation?

The value of R used to avoid saturation should be chosen carefully, as both larger and smaller values can have drawbacks. A larger value of R will decrease the gain, but may also introduce instability. A smaller value of R will increase the gain, but may also increase noise and distortion in the circuit. It is important to find a balance between these factors for optimal performance.

## 4. What happens if the op amp does reach saturation?

If the op amp does reach saturation, the output voltage will become limited to the power supply rails, resulting in distortion of the output signal. This can also cause the circuit to become unstable and produce unexpected results. It is important to choose an appropriate value of R to avoid saturation in order to maintain the desired performance of the circuit.

## 5. Are there any other factors besides R that can affect op amp saturation?

Yes, there are other factors that can affect op amp saturation, such as the input voltage range, supply voltage, and input and output impedances. It is important to consider all of these factors when designing a circuit to ensure the op amp operates within its recommended parameters and avoids saturation.

Replies
13
Views
2K
Replies
4
Views
2K
Replies
17
Views
2K
Replies
3
Views
2K
Replies
8
Views
2K
Replies
13
Views
2K
Replies
13
Views
2K
Replies
11
Views
2K
Replies
18
Views
3K
Replies
4
Views
1K