High-fidelity D-type audio frequency amplifier chip with noise canceller circuit

Abstract

The invention relates to a high-fidelity D-type audio frequency amplifier, in particular to a high-fidelity D-type audio frequency amplifier chip with a noise canceller circuit. The high-fidelity D-type audio frequency amplifier chip comprises a pre-amplifier, a second-level amplifier, a PWM circuit, a driver, a power amplifier and a feedback circuit. The high-fidelity D-type audio frequency amplifier chip is characterized in that the noise canceller circuit is included, the noise canceller circuit is connected with the driver and the pre-amplifier, the noise canceller circuit turns on and off the power amplifier through the driver during electrifying and power failure of the chip, an audio input end is subjected to clamping during a recovery process of the chip, so that the chip is in a soft-starting working mode, the noise canceller circuit comprises a logic unit, a switch capacitance integrator and a control unit, the logic unit, the switch capacitance integrator and the control unit are connected, the switch capacitance integrator and the control unit are connected, the control unit is connected with the input end of the pre-amplifier, and the logic unit is connected with the driver. The high-fidelity D-type audio frequency amplifier chip is mainly used for the audio frequency amplifier.

Description

technical field [0001] The invention relates to a high-fidelity Class D audio amplifier, in particular to a blasting noise control circuit in the Class D audio amplifier. Background technique [0002] Click-and-pop is called click and pop, and it belongs to a type of popping noise in Class D audio amplifiers. For the vast majority of people, if the click-and-pop is not very loud, it is still acceptable, but if the harsh sound is too loud, it will make people feel irritated and affect the normal use of the audio amplifier. Therefore, it is extremely important for the audio amplifier circuit to eliminate or reduce the click-and-pop noise. [0003] In general, click-and-pop acoustic energy is defined as the audible noise generated by voltage transients generated by an amplifier system that do not originate from the system's input signal. Among the many causes of the click-and-pop sound, one of the main reasons is that the normal working point of the chip is not established or...

AI Technical Summary

Problems solved by technology

However, the disadvantage of these methods is that they can only be improved for a certain type of noise, and it is difficult to eliminate most of the blasting noise in the equipment.

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