A class ab audio power amplifier

Abstract

The embodiment of the present invention discloses a class AB audio power amplifier, the amplifier includes: an input circuit, a bias circuit, an amplification circuit, an output circuit, a common-mode feedback circuit and a Miller compensation circuit, and the amplification circuit includes a first composition circuit , a second composition circuit and a third composition circuit, the third composition circuit includes a seventh transistor and an eighth transistor in addition to the ninth transistor and the tenth transistor; the gate of the seventh transistor is connected to the fifth The bias voltage is electrically connected, the source is electrically connected to the drain of the ninth transistor, the drain is electrically connected to the first end of the first component circuit, and the substrate is grounded; the gate of the eighth transistor is electrically connected to the eighth transistor. The fifth bias voltage is electrically connected, the source is electrically connected to the drain of the tenth transistor, the drain is electrically connected to the second end of the first component circuit, and the substrate is grounded, so as to achieve a wider voltage range within, the voltage gain of the amplifier does not vary with the supply voltage V PVDD change with changes.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a class AB audio power amplifier. Background technique [0002] With the improvement of science and technology, power integrated circuits develop rapidly. Power integrated circuits refer to integrated circuits that integrate high-voltage power devices, signal processing systems, peripheral drive circuits, interface circuits, protection circuits, and detection circuits on the same chip. Audio power amplifiers are an important part of power integrated circuits and are widely used in consumer electronics. [0003] Such as figure 1 as shown, figure 1 A schematic diagram of a circuit structure of an existing class AB audio power amplifier is shown. The supply voltage V of the existing Class AB audio power amplifier PVDD will fluctuate within a certain range, when the supply voltage V PVDD When rising to a certain voltage, the drain voltage of transistors M9 and M10 w...

AI Technical Summary

Problems solved by technology

The supply voltage V of the existing Class AB audio power amplifier PVDD will fluctuate within a certain range, when the supply voltage V PVDD When rising to a certain voltage, the drain voltage of transistors M9 and M10 will increase with V PVDD rises, making the drain-substrate voltage difference V of transistors M9 and M10 DB increases, causing drain-substrate leakage currents of transistors M9 and M10, reducing the gain of the class AB audio power amplifier

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