Audio device for reducing pop noise and processing method thereof

Patent metadata

Field	Value
Publication number	US-11114984-B2
Application number	US-201916520999-A
Country	US
Kind code	B2
Filing date	Jul 24, 2019
Priority date	Feb 1, 2019
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

An audio device for reducing pop noise is adapted to compensate for a direct current (DC) offset of an audio source signal and output the audio source signal to an audio playing device. The audio device includes a linear operation circuit, an adder, a digital-to-analog circuit, and an amplification circuit. The digital-to-analog circuit is coupled between the adder and the amplification circuit. The linear operation circuit generates a DC offset value based on a linear equation, a temperature parameter, a slope parameter, and a constant. The adder is configured to process an input signal and the DC offset value to generate a calibration signal. The digital-to-analog circuit is configured to convert a calibration signal in a digital form to a calibration signal in an analog form. The amplification circuit is configured to process the calibration signal in the analog form to output the audio source signal.

First claim

What is claimed is:

1. An audio device for reducing pop noise, adapted to compensate for a direct current (DC) offset value of an audio source signal and output the audio source signal to an audio playing device, the audio device comprising:
a linear operation circuit for generating the DC offset value based on a linear equation, a temperature parameter, a slope parameter, and a constant, wherein the linear equation is:
Y=M*X+C

wherein Y is the DC offset value, X is the temperature parameter, M is the slope parameter, and C is the constant;
an adder for processing an input signal and the DC offset value to generate a calibration signal;
a digital-to-analog circuit coupled to the adder, the digital-to-analog circuit being configured to convert the calibration signal in a digital form to the calibration signal in an analog form;
an amplification circuit coupled to the digital-to-analog circuit, the amplification circuit being configured to process the calibration signal in the analog form to output the audio source signal;
a temperature sensing circuit coupled to the linear operation circuit, the temperature sensing circuit generating the temperature parameter based on a temperature of the audio device and outputting the temperature parameter to the linear operation circuit;
a storage device coupled to the linear operation circuit, the storage device being configured to store the slope parameter and the constant and output the slope parameter and the constant to the linear operation circuit; and
a switch coupled to the amplification circuit, the switch being configured to control an output of the audio device, wherein when the switch is closed, the audio device outputs the audio source signal, and when the switch is opened, the audio device does not output the audio source signal.

2. The audio device according to claim 1 , further comprising:
a control circuit; and
an audio output terminal coupled to the control circuit, the audio output terminal being configured to output the audio source signal to the audio playing device, wherein when the audio output terminal is coupled to the audio playing device, the audio output terminal outputs a coupling signal to the control circuit, and when the audio output terminal is not coupled to the audio playing device, the audio output terminal outputs a disconnection signal to the control circuit.

3. The audio device according to claim 2 , wherein when the control circuit receives the coupling signal, the audio device compensates for the DC offset of the audio source signal based on a power-up process, the power-up process comprising:
enabling the digital-to-analog circuit, the amplification circuit, the temperature sensing circuit, and the storage device;
enabling the linear operation circuit; and
outputting, by the control circuit, an on signal to close the switch.

4. The audio device according to claim 2 , wherein the control circuit outputs an off signal based on the disconnection signal to open the switch.

5. An audio device for reducing pop noise, adapted to compensate for a direct current (DC) offset value of an audio source signal and output the audio source signal to an audio playing device, the audio device comprising:
a linear operation circuit for generating the DC offset value based on a linear equation, a temperature parameter, a slope parameter, and a constant, wherein the linear equation is:
Y=M*X+C

wherein Y is the DC offset value, X is the temperature parameter, M is the slope parameter, and C is the constant;
an adder for processing an input signal and the DC offset value to generate a calibration signal;
a digital-to-analog circuit coupled to the adder, the digital-to-analog circuit being configured to convert a calibration signal in a digital form to a calibration signal in an analog form;
an amplification circuit coupled to the digital-to-analog circuit, the amplification circuit being configured to process the calibration signal in the analog form to output the audio source signal;
a temperature sensing circuit coupled to the linear operation circuit, the temperature sensing circuit generating the temperature parameter based on a temperature of the audio device and outputting the temperature parameter to the linear operation circuit;
a storage device coupled to the linear operation circuit, the storage device being configured to store the slope parameter and the constant and output the slope parameter and the constant to the linear operation circuit;
an analog-to-digital circuit coupled to the amplification circuit, the analog-to-digital circuit being configured to sense an uncompensated DC offset value of the audio source signal; and
a control circuit coupled between the analog-to-digital circuit and the storage device, the control circuit adjusting the slope parameter and the constant based on the uncompensated DC offset value of the audio source signal and outputting the slope parameter and the constant to the storage device.

6. An audio processing method for reducing pop noise, adapted to compensate for a direct current (DC) offset value of an audio source signal, the audio processing method comprising:
obtaining a slope parameter and a constant;
generating a temperature parameter based on a temperature of an audio device;
generating the DC offset value based on a linear equation, the temperature parameter, the slope parameter, and the constant, wherein the linear equation is:
Y=M*X+C

wherein Y is the DC offset value, X is the temperature parameter, M is the slope parameter, and C is the constant;
processing an input signal and the DC offset value to generate a calibration signal;
converting the calibration signal in a digital form to the calibration signal in an analog form;
processing the calibration signal in the analog form to output the audio source signal; and
using a switch to control an output of the audio device, wherein when the switch is closed, the audio device outputs the audio source signal, and when the switch is opened, the audio device does not output the audio source signal.

7. An audio processing method for reducing pop noise, adapted to compensate for a direct current (DC) offset value of an audio source signal, the audio processing method comprising:
obtaining a slope parameter and a constant;
generating a temperature parameter based on a temperature of an audio device;
generating the DC offset value based on a linear equation, the temperature parameter, the slope parameter, and the constant, wherein the linear equation is:
Y=M*X+C

wherein Y is the DC offset value, X is the temperature parameter, M is the slope parameter, and C is the constant;
processing an input signal and the DC offset value to generate a calibration signal;
converting the calibration signal in a digital form to the calibration signal in an analog form;
processing the calibration signal in the analog form to output the audio source signal;
sensing an uncompensated DC offset value of the audio source signal; and
adjusting the slope parameter and the constant based on the uncompensated DC offset value of the audio source signal.

Assignees

• Realtek Semiconductor Corp

Inventors

• Lin Shih-Hsin
• Lin Che-Hung
• Tu Yi-Chang

Classifications

• H03F2200/03

  the amplifier being designed for audio applications · CPC title

• H03F2200/507

  A switch being used for switching on or off a supply or supplying circuit in an IC-block amplifier circuit · CPC title

• H03G3/348

  Muting in response to a mechanical action or to power supply variations, e.g. during tuning; Click removal circuits · CPC title

• H03F1/305 Primary

  in case of switching on or off of a power supply · CPC title

• H03M1/0881

  by forcing a gradual change from one output level to the next, e.g. soft-start · CPC title