Yes this information helps. I will do some more homework. Thank youOperational amplifiers in and of themselves don't have to satisfy any conditions to be linear. If the application allows it, they will be linear. If it does not allow them to be linear, they won't be. What are some examples:
Does this convey some feel for the situation?
- If the amplifier is in an open loop configuration the output will likely be as close to the rails as it can possibly get due to the high gain and the internal construction.
- If the amplifier is configured to perform a non linear task such as being a limiter. This is a non-linear transfer function.
- If the amplifier is configured as a multiplier. This is also a non-linear function.
- If the amplifier is configured as a low pass filter. This is a linear function.
- If the amplifier is configured as a difference amplifier, this is also a linear function.
Hi,An LM358 dial or LM324 quad opamp are not linear because they are designed for low power supply idle current therefore they have crossover distortion, noise and a poor high frequency response.
Do you mean the op amp itself or the circuit the op amp is put into?What are the conditions an operational amplifier must satisfy to be linear?
As far as the -72 model, that's not a bad choice. A little bit more expensive in 1 piece quantities, but about 4 times more in large quantities that could be a problem but maybe you can find cheaper i didnt want to look everywhere for pricing.There are hundreds or maybe thousands of opamps available. The LM358 and LM324 opamps are the only ones I know that have severe crossover distortion and lots of noise. A few other opamps have their limited frequency response.
I have replaced LM358 dual opamps with an MC33172 and replaced LM324 quad opamps with an MC33174. They have NO crossover distortion, much wider 30kHz power bandwidth, same low idle current, same input common mode to the negative supply or ground, same minimum supply of 3V and a typical noise spec that seems lower than the no noise specs for the LM358 and LM324 opamps. The MC33172 is made in only surface-mount packages today.
The high gain and the feedback make operational amplifiers a great deal more useful than they might be otherwise.An operational amplifier will be linear if the output has a linear relationship to its input. This statement is simple, exact, and not actually very useful. Op-amps are normally used in circuit configurations where the high open-loop gain is used to minimize non-linear characteristics. Properties of an op-amp that minimize circuit non-linearity are high open-loop gain, low input offset voltage, high input impedance, low output impedance, and high frequency response for low dynamic distortion.
The main required feature is "negative feedback" that's the key point for linear operation.An operational amplifier will be linear if the output has a linear relationship to its input. This statement is simple, exact, and not actually very useful. Op-amps are normally used in circuit configurations where the high open-loop gain is used to minimize non-linear characteristics. Properties of an op-amp that minimize circuit non-linearity are high open-loop gain, low input offset voltage, high input impedance, low output impedance, and high frequency response for low dynamic distortion.
Negative feedback is not a feature of the op-amp, but rather of the circuit in which the op-amp is used.The main required feature is "negative feedback"
Yes, and that is why i said negative feedback is a requirement for linear operation. You cant operate an op amp in linear mode without negative feedback.Negative feedback is not a feature of the op-amp, but rather of the circuit in which the op-amp is used.
Of course you are correct. However, the original question was: "What are the conditions an operational amplifier must satisfy to be linear?" Whereas negative feedback is a condition the external circuit must satisfy. Maybe that is splitting hairs, but it's what I do.Yes, and that is why i said negative feedback is a requirement for linear operation.
Hi again,Of course you are correct. However, the original question was: "What are the conditions an operational amplifier must satisfy to be linear?" Whereas negative feedback is a condition the external circuit must satisfy. Maybe that is splitting hairs, but it's what I do.