Process Engineering Division – Instrumentation and Automation Section – Daily Question – Question from 2020-08-11
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Process Engineering Division – Instrumentation and Automation Section – Daily Question – Question from 2020-08-11: Discussion question: 201. What is the purpose of introducing negative feedback in an amplification circuit?
Introducing negative feedback into an amplification circuit reduces the amplification factor, but it enables many of the circuit’s performance characteristics to be improved. For example, as in 1653, it can stabilize the quiescent operating point and gain, expand the bandwidth, reduce nonlinear distortion, and change the input resistance and output impedance. (1) Voltage negative feedback stabilizes the output voltage of the amplification circuit, thereby reducing the output impedance ； (2) Current negative feedback stabilizes the output current of the amplification circuit, thereby increasing the output impedance ； (3) Series negative feedback increases the input impedance by inserting a feedback path at the input ； (4) Parallel negative feedback reduces the input impedance because a feedback branch is connected in parallel at the input.
It is compared with the input signal, thereby stabilizing the output of the amplification circuit so that it varies within a certain range.
Introducing negative feedback into an amplification circuit reduces the gain, but it improves many of the circuit’s performance characteristics. For example, it can stabilize the quiescent point and gain, expand the bandwidth, reduce nonlinear distortion, and change the input resistance and output impedance. (1) Voltage negative feedback stabilizes the output voltage of the amplification circuit, thereby reducing the output impedance ； (2) Current negative feedback stabilizes the output current of the amplification circuit, thereby increasing the output impedance ； (3) Series negative feedback increases the input impedance by inserting a feedback path at the input ； (4) Parallel negative feedback reduces the input impedance because a feedback branch is connected in parallel at the input.
By introducing negative feedback into an amplification circuit, although the gain is reduced, many of the performance characteristics of the amplification circuit can be improved. For example, it can stabilize the quiescent point and gain, expand the bandwidth, reduce nonlinear distortion, and change the input resistance and output impedance. (1) Voltage negative feedback stabilizes the output voltage of the amplification circuit, thereby reducing the output impedance ； (2) Current negative feedback stabilizes the output current of the amplification circuit, thereby increasing the output impedance ； (3) Series negative feedback increases the input impedance by inserting a feedback path at the input ； (4) Parallel negative feedback reduces the input impedance because a feedback branch is connected in parallel at the input.
By introducing negative feedback into an amplification circuit, although the gain is reduced, many of the performance characteristics of the amplification circuit can be improved. For example, it can stabilize the quiescent point and gain, expand the bandwidth, reduce nonlinear distortion, and change the input resistance and output impedance. (1) Voltage negative feedback stabilizes the output voltage of the amplification circuit, thereby reducing the output impedance ； (2) Current negative feedback stabilizes the output current of the amplification circuit, thereby increasing the output impedance ； (3) Series negative feedback increases the input impedance by inserting a feedback path at the input ； (4) Parallel negative feedback reduces the input impedance because a feedback branch is connected in parallel at the input.
Introducing negative feedback in an amplification circuit can stabilize the quiescent operating point, stabilize the gain, alter the input and output resistances, expand the bandwidth, and reduce nonlinear distortion.
Introducing negative feedback into an amplification circuit reduces the gain, but it improves many of the circuit’s performance characteristics.
Introducing negative feedback into an amplification circuit reduces the amplification factor, but it enables many of the circuit’s performance characteristics to be improved. For example, as in 1653, it can stabilize the quiescent operating point and gain, expand the bandwidth, reduce nonlinear distortion, and change the input resistance and output impedance. (1) Voltage negative feedback stabilizes the output voltage of the amplification circuit, thereby reducing the output impedance ； (2) Current negative feedback stabilizes the output current of the amplification circuit, thereby increasing the output impedance ； (3) Series negative feedback increases the input impedance by inserting a feedback path at the input ； (4) Parallel negative feedback reduces the input impedance because a feedback branch is connected in parallel at the input.
The introduction of negative feedback is primarily intended to keep the amplification circuit operating in the linear region, to ensure that the output voltage does not exceed the maximum output voltage, and to reduce nonlinear distortion.