Audio amplification circuit

Abstract

The invention discloses an audio amplification circuit comprising an audio power amplifier, a boosting conversion circuit and a control circuit, wherein the control circuit is used for generating a first control signal and a second control signal; the boosting conversion circuit is connected with the control circuit and the audio power amplifier and is used for converting power voltage to high voltage under the control of the first control signal, and the high voltage is used for supplying power to the audio power amplifier; the audio power amplifier is connected with the control circuit and is used for amplifying an audio input signal under the control of the second control signal and outputting an audio output signal; the boosting conversion circuit is used for sending a signal of successful establishment to the control circuit after the high voltage is established; and the control circuit sends the second control signal to the audio power amplifier after receiving the signal of successful establishment. The audio amplification circuit effectively eliminates starting noises caused by an independent control circuit.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to an audio amplifier circuit. Background technique [0002] Nowadays, lithium batteries are usually used for power supply in portable systems. Due to the limitation of lithium battery voltage (usually up to 4.2V), the audio amplifier circuit power rail in the system is only up to 4.2V. If the differential output method is used, the output Peak V P The highest can reach about 4V, if there is no obvious truncated distortion, if the system load R L When it is 8Ω, the output power of the audio amplifier circuit In order to obtain better sound quality and greater volume, it is necessary to increase the power supply rail of the audio amplifier circuit. [0003] The traditional method usually uses a charge pump or an inductive DC-DC (direct-direct current) boost converter to increase the voltage of the lithium battery, supply the power after the voltage boost to the audio ...

AI Technical Summary

Problems solved by technology

[0012] This is because the class D amplifier 20 is powered by high-voltage PVDD, and the class D amplifier 20 must be started after the high-voltage PVDD is stable, otherwise it will cause problems such as startup noise, but when using different control circuits, the system does not know the high-voltage PVDD Therefore, it may cause the high-voltage PVDD to be established, and the class D amplifier 20 has already started, thereby causing the problem of startup noise

[0013] Similarly, when using other types of audio power amplifiers (such as Class A amplifiers, Class B amplifiers, etc.), the problem of starting noise will also occur due to the independent existence of the control circuit.

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