# US 2025/0219601 A1 · Circuits, devices and methods related to audio amplifiers having gain calibration

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- Number: US 2025/0219601 A1
- Document ID: US20250219601A1
- Status: Published application
- Kind: A1
- Application number: 19/001,274
- Filed: 2024-12-24
- Published: 2025-07-03
- Earliest claimed: 2021-09-29
- Assignees: Skyworks Solutions, Inc.
- Applicants: Skyworks Solutions, Inc.
- Inventors: Spencer David LEUENBERGER; Deepika KUMARI; David LAMB; Mark R. PETING; Evan Michael ALBRIGHT; Wai Laing LEE; Amit KUMAR
- Web page: https://patentgrep.com/patent/US20250219601A1

## CPC

- H03F 3/2175: {using analogue-digital or digital-analogue conversion (H03F3/2173 takes precedence)}
- H03F 3/183: with semiconductor devices only
- H03F 3/187: in integrated circuits
- H03F 3/2173: {of the bridge type}
- H03G 3/3005: {in amplifiers suitable for low-frequencies, e.g. audio amplifiers (H03G3/32, H03G3/34 take precedence)}
- H04R 1/1041: {Mechanical or electronic switches, or control elements (switches in general H01H)}
- H04R 3/04: for correcting frequency response
- H03F 2200/03: the amplifier being designed for audio applications
- H03F 2200/351: Pulse width modulation being used in an amplifying circuit
- H03G 2201/103: being an amplifying element
- H04R 2201/028: Structural combinations of loudspeakers with built-in power amplifiers, e.g. in the same acoustic enclosure (H04R2499/10 takes precedence; Single (sub)woofer with two or more satellite loudspeakers for mid- and high-frequency band reproduction driven via the (sub)woofer H04R2205/026)
- H04R 2420/07: Applications of wireless loudspeakers or wireless microphones
- H04R 2430/01: Aspects of volume control, not necessarily automatic, in sound systems
- H03F: AMPLIFIERS
- H03G: CONTROL OF AMPLIFICATION
- H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K)

## Abstract

A method for calibrating an audio amplification system can include injecting a tone having a frequency to an input path of an audio amplifier, such that an input signal provided to the audio amplifier includes the tone signal. The method can further include sampling an output signal at an output node of the audio amplifier, and sampling the input signal at an input node of the audio amplifier. The method can further include generating a correction signal based on the sampled output signal and the sampled input signal to correct for a gain variation of the audio amplifier.

## Claims

### Claim 1

A calibration circuit for an audio amplification system, comprising:
a tone generator configured to provide a tone having a frequency to an input path of an audio amplifier, such that an input signal provided to the audio amplifier includes the tone;
a first sampling circuit configured to sample an output signal at an output node of the audio amplifier;
a second sampling circuit configured to sample the input signal at an input node of the audio amplifier; and
a gain adjustment circuit configured to generate a correction signal based on the sampled output signal and the sampled input signal to correct for a gain variation of the audio amplifier.

### Claim 2

(canceled)

### Claim 3

(canceled)

### Claim 4

(canceled)

### Claim 5

(canceled)

### Claim 6

(canceled)

### Claim 7

(canceled)

### Claim 8

(canceled)

### Claim 9

(canceled)

### Claim 10

(canceled)

### Claim 11

(canceled)

### Claim 12

(canceled)

### Claim 13

A method for calibrating an audio amplification system, the method comprising:
injecting a tone having a frequency to an input path of an audio amplifier, such that an input signal provided to the audio amplifier includes the tone signal;
sampling an output signal at an output node of the audio amplifier;
sampling the input signal at an input node of the audio amplifier; and
generating a correction signal based on the sampled output signal and the sampled input signal to correct for a gain variation of the audio amplifier.

### Claim 14

An audio amplification system comprising:
a digital audio path configured to provide a digital signal;
an audio amplifier configured to receive the digital signal as an input signal and generate an output signal; and
a calibration circuit including a tone generator configured to inject a tone having a frequency to the digital audio path, such that the input signal includes the tone, the calibration circuit further including a first sampling circuit configured to sample the output signal at an output node of the audio amplifier, and a second sampling circuit configured to sample the input signal at an input node of the audio amplifier, the calibration circuit further including a gain adjustment circuit configured to generate a correction signal based on the sampled output signal and the sampled input signal to correct for a gain variation of the audio amplifier.

### Claim 15

(canceled)

### Claim 16

(canceled)

### Claim 17

(canceled)

### Claim 18

(canceled)

### Claim 19

(canceled)