What about the dynamic class A sliding bias circuit for differential transmission of power amplifier?

Super Class A amplifier is a circuit form of amplifier, which is often used for power amplification and has applications in both low-frequency electronic circuits and high-frequency electronic circuits. Super Class A amplifier, which is common in the field of high fidelity, is an application form of super Class A amplifier.

Characteristics of 1

Compared with the common class A amplifier, the similarities and differences are as follows:

similar

1. During the whole period of the signal (plus or minus two and a half periods of the signal), any device of the amplifier has current flowing without current cut-off.

2. Based on the above characteristics, it has the advantage of no cross distortion, which is particularly meaningful for audio amplification.

3. The efficiency of super class A amplifier composed of single-ended circuit is low. Theoretically,

discrepancy

1. Active devices (such as transistors) adopt dynamic bias instead of fixed bias in ordinary class A amplifiers.

2. Based on the above reasons, its advantage is that when amplifying large dynamic range signals, the overall efficiency is much higher than that of ordinary class A amplifiers. Especially push-pull super class A amplifier, the efficiency is close to that of class B amplifier.

2 application

As mentioned above, super class A amplifier has the advantages of no cross distortion and higher efficiency than class A amplifier.

Based on this, super class A power amplifier is widely used in the field of high fidelity.

In addition, super class A amplifiers are also widely used in high-frequency linear power amplifiers.

3 technical difficulties

The biggest technical difficulty of Super Class A is the dynamic bias circuit, which can adjust the bias according to the signal strength.