# US 11,309,857 B2 · Audio playback device and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,309,857 B2 - Document ID: US11309857B2 - Status: Granted - Kind: B2 - Application number: 16/874,821 - Filed: 2020-05-15 - Published: 2020-11-19 - Granted: 2022-04-19 - Earliest claimed: 2019-05-16 - Assignees: Realtek Semiconductor Corp. - Applicants: Realtek Semiconductor Corporation - Inventors: Li-Lung Kao; Chia-Chi Tsai - Web page: https://patentgrep.com/patent/US11309857B2 ## CPC - H03G 3/3005: {in amplifiers suitable for low-frequencies, e.g. audio amplifiers (H03G3/32, H03G3/34 take precedence)} - H03F 3/183: with semiconductor devices only - H03F 2200/03: the amplifier being designed for audio applications - H03G 2201/103: being an amplifying element - H03G: CONTROL OF AMPLIFICATION - H03F: AMPLIFIERS ## Abstract A device is provided that includes a plurality of signal processing paths coupled in parallel, an adding circuit and an amplifier circuit. The number of the signal processing paths is N and each of the signal processing paths receives a same input signal to generate an output analog signal after a signal processing is performed, wherein each of the signal processing paths at least includes a DAC circuit and the signal processing at least includes a digital to analog conversion corresponding to the DAC circuit. The adding circuit adds the output analog signal generated from each of the signal processing paths to generate a total output analog signal. The amplifier circuit receives the total output analog signal to adjust a signal intensity of the total output analog signal according to a gain to generate an output audio signal, wherein the gain is 1/N. ## Claims ### Claim 1 A device, comprising: a plurality of signal processing paths coupled in parallel, the number of the signal processing paths being N and each of the signal processing paths being configured to receive a same input signal to generate an output analog signal after a signal processing is performed, each of the signal processing paths at least including a digital to analog converting (DAC) circuit and the signal processing at least includes a digital to analog conversion performed by the DAC circuit; an adding circuit configured to add the output analog signal generated from each of the signal processing paths to generate a total output analog signal; and an amplifier circuit configured to receive the total output analog signal for adjusting a signal intensity of the total output analog signal according to a gain for generating an output audio signal, the gain being 1/N. ### Claim 2 (depends on 1) The device of claim 1, wherein each of the signal processing paths forces the output analog signal to have an output noise, and a total output noise of the output audio signal generated by the amplifier circuit is √{square root over (N×(1/N2))} times of the output noise. ### Claim 3 (depends on 1) The device of claim 1, wherein each of the signal processing paths further comprises a pre-processing circuit electrically coupled behind the DAC circuit, and the signal processing further comprises a signal amplification performed by the pre-processing circuit. ### Claim 4 (depends on 3) The device of claim 3, wherein the amplifier circuit is a post-amplifier circuit or a post-driving circuit. ### Claim 5 (depends on 3) The device of claim 3, wherein the pre-processing circuit is a pre-amplifier circuit or a pre-driving circuit. ### Claim 6 (depends on 1) The device of claim 1, wherein each of the signal processing paths further comprises a digital modulation circuit electrically coupled in front of the DAC circuit, and the signal processing comprises a signal modulation process performed by the digital modulation circuit. ### Claim 7 An audio playback method, comprising: receiving a same input signal by each of a plurality of signal processing paths coupled in parallel to generate an output analog signal after a signal processing is performed, wherein the number of the signal processing paths is N and each of the signal processing paths at least comprises a digital to analog converting (DAC) circuit and the signal processing at least comprises a digital to analog conversion performed by the DAC circuit; adding the output analog signal generated from each of the signal processing paths by an adding circuit to generate a total output analog signal; and receiving the total output analog signal by an amplifier circuit to adjust a signal intensity of the total output analog signal according to a gain to generate an output audio signal, wherein the gain is 1/N. ### Claim 8 (depends on 7) The audio playback method of claim 7, wherein each of the signal processing paths forces the output analog signal to have an output noise, and a total output noise of the output audio signal generated by the amplifier circuit is √{square root over (N×(1/N2))} times of the output noise. ### Claim 9 (depends on 7) The audio playback method of claim 7, wherein each of the signal processing paths further comprises a pre-processing circuit electrically coupled behind the DAC circuit, and the signal processing further comprises a signal amplification performed by the pre-processing circuit. ### Claim 10 (depends on 9) The audio playback method of claim 9, wherein the amplifier circuit is a post-amplifier circuit or a post-driving circuit. ### Claim 11 (depends on 9) The audio playback method of claim 9, wherein the pre-processing circuit is a pre-amplifier circuit or a pre-driving circuit. ### Claim 12 (depends on 7) The audio playback method of claim 7, wherein each of the signal processing paths further comprises a digital modulation circuit electrically coupled in front of the DAC circuit, and the signal processing comprises a signal modulation process performed by the digital modulation circuit.