Dynamic balancing class-A audio power amplifier

Abstract

The invention relates to a dynamic balancing class-A audio power amplifier, and complementary error sampling circuits and bias voltage control circuits are respectively arranged in bridge arm circuits which are arranged at the left and the right and are the same; each complementary error sampling circuit consists of an output-stage current sampling resistor and a complementary error amplification inverter, the input ends of the complementary error amplification inverters are respectively connected with the output-stage current sampling resistors, and the output ends of the complementary error amplification inverters are respectively connected with the control ends of an upper controllable constant-current source and a lower controllable constant-current source; and the bias voltage control circuits respectively consist of the upper and the lower controllable constant current sources and bias voltage resistors, two ends of the bias voltage resistors are respectively connected with the upper and the lower controllable constant current sources and bases of power complementary pipes, the upper and the lower controllable constant current sources are connected through series connection of the bias voltage resistors, and the other ends are respectively connected with a positive working power supply and a negative working power supply. The dynamic balancing class-A audio power amplifier can realize the purposes of minimizing output stage linear distortion, leading frequency response to be widest and preventing power supply properties from affecting sound quality in the aspects of principle and technology. The bias voltage control circuits can be applied as super class-A bias control circuits.

Description

technical field [0001] The invention relates to the field of high-fidelity audio power amplifiers, in particular to a dynamically balanced Class A audio power amplifier. Background technique [0002] Classic audio power amplifiers can be divided into Class A, Class A and B, and Class B according to the static bias current state of the output stage; according to the circuit structure, they can be divided into single-ended, push-pull, and balanced (bridge) and other types. , Among them, the sound performance of the balanced Class A audio power amplifier is the best. [0003] Its working characteristics are analyzed as follows: In the ideal case of no linear distortion in the output stage, the voltage and current of the input in-phase signal and anti-phase signal are equal in magnitude and opposite in phase, and the current flowing through the two arms of the bridge is also equal in magnitude and in phase On the contrary, that is, the sum of the currents flowing through the tw...

AI Technical Summary

Problems solved by technology

When using a balanced output stage, due to the randomness of the static bias current changes of the two arms of the bridge, they cannot cancel each other out, so there is always a current that changes with the input signal in the total power supply current, and the ideal working state cannot be achieved.

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