Analog and electronic circuits

Which metric is used to judge whether a negative-feedback amplifier operates stably without oscillating?

  1. APhase margin
  2. BSlew rate
  3. CInput offset voltage
Show answer and explanation

Answer: A. Phase margin

Phase margin is how far the phase lag is from 180° at the frequency where the loop gain is 1 (0 dB). With a small margin, the step response rings or the circuit oscillates. Designs generally aim for a phase margin of about 45° to 60° or more.

Practice this topic Back to topic

More Analog and electronic circuits questions

  1. Compared with a class A amplifier, which is a characteristic of a class B push-pull amplifier?
  2. When a current of 1 mA flows through a 10 kΩ resistor, what is the voltage across it?
  3. What is the combined resistance of two 10 kΩ resistors connected in parallel?
  4. Two 10 kΩ resistors are connected in series across a 10 V supply. What is the voltage at the point between them (relative to ground)?
  5. How does the magnitude of a capacitor's impedance (capacitive reactance) change as frequency increases?