Unbiased voltage detection principle of post amplifier

1. Bias current setting: In the post-amplifier, a bias current is usually set to adjust the position of the static operating point of the o

Unbiased voltage detection principle of post amplifier

1. Bias current setting: In the post-amplifier, a bias current is usually set to adjust the position of the static operating point of the output stage. The bias current determines the correct working range of the output stage.

2. Bias voltage reference: The bias voltage reference value is generated by dividing the bias current through a resistor.

3. Phase compensation: A common technique is to apply phase compensation. By introducing a feedback element, a specific phase difference is generated between the output signal and the input signal. In bias voltage detection, the phase compensation circuit is used to generate a reference voltage related to the phase of the input signal.

4. Bias control: compare the reference voltage generated by the phase compensation circuit with the bias voltage reference to obtain the difference between them. The differential voltage is used to adjust the working state of the post amplifier.

5. Difference detection and protection: After detecting the difference between the bias voltage and the phase compensation reference voltage, the post-amplifier will trigger protection measures, such as disconnecting the input signal, lowering the output signal level or changing the working state, so as to protect the amplifier from potential damage.