I suddenly designed a multiple feedback amplifier circuit. I would like to ask you about the advantages of this circuit.

qwerqwer_1

I suddenly designed a multiple feedback amplifier circuit. I would like to ask you about the advantages of this circuit. [Copy link]

I designed a multiple feedback circuit on a whim and solved the transfer function. Not only is it difficult to solve, but I also found out through random tests that the stability is average. I would like to ask what you guys think?

maychang

I remember that OP37 is an op amp with a very high unity gain bandwidth. What do you want to do by adding a resistor R10 to the circuit?

qwerqwer_1

maychang posted on 2023-12-6 16:21 OP37 remembers that it is an op amp with a very high unity gain bandwidth. What do you want to do by adding a resistor R10 to the circuit?

On a whim, I wanted to try to increase the intensity of negative feedback to improve the system's ability to suppress noise or drift.

maychang

qwerqwer_1 posted on 2023-12-6 17:17 I suddenly had an idea and wanted to try to increase the intensity of negative feedback to improve the system's ability to suppress noise or drift

[I want to try to increase the intensity of negative feedback to improve the system's ability to suppress noise or drift]

Adding R10 is useless. To improve the system's ability to suppress noise or drift, just modify the values of R6 and R7 in the second figure.

maychang

qwerqwer_1 posted on 2023-12-6 17:17 I suddenly had an idea and wanted to try to increase the intensity of negative feedback to improve the system's ability to suppress noise or drift

In addition, the signal source frequency in the figure is 1kHz. If such a low frequency signal needs to be amplified 120 times, a single-stage op amp is sufficient, and there is no need to use a second-stage amplifier.