# US 11,910,171 B2 · Smart speaker power management > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,910,171 B2 - Document ID: US11910171B2 - Status: Granted - Kind: B2 - Application number: 17/111,967 - Filed: 2020-12-04 - Published: 2022-03-10 - Granted: 2024-02-20 - Earliest claimed: 2020-09-04 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Zhigang Dang; Daniel Naito; Evan Thompson; Peter Poon; Manasi Lagare; Michael Nussbaum; David Sumberg - Web page: https://patentgrep.com/patent/US11910171B2 ## CPC - H04R 3/007: {Protection circuits for transducers} - H03F 1/025: {by using a signal derived from the input signal} - H03F 1/52: Circuit arrangements for protecting such amplifiers {(monitoring arrangements G01R31/28; increasing reliability in communication systems, e.g. using redundancy H04B1/74)} - H03F 3/181: Low-frequency amplifiers, e.g. audio preamplifiers - H03F 3/183: with semiconductor devices only - H03F 3/72: Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal - H03G 3/3005: {in amplifiers suitable for low-frequencies, e.g. audio amplifiers (H03G3/32, H03G3/34 take precedence)} - H03G 3/348: {Muting in response to a mechanical action or to power supply variations, e.g. during tuning; Click removal circuits} - H03F 2200/03: the amplifier being designed for audio applications - H03F 2200/321: Use of a microprocessor in an amplifier circuit or its control circuit - 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) - H03F: AMPLIFIERS - H03G: CONTROL OF AMPLIFICATION ## Abstract A smart speaker power controller may be configured to receive power conforming to one of a plurality of power modes from an input power source. The power controller may be further configured to communicate the power mode to at least one component of a processing system or at least one component of an audio system for operating the smart speaker according to the received power mode, including determining a current limit of a power converter; determining a shutdown voltage threshold and safely shutting down the smart speaker if the input voltage falls below the threshold, and/or modifying audio operation of the smart speaker in response to the power mode. The smart speaker can further include an audio power supply controller configured to monitor energy required to reproduce an audio signal and to servo a power supply voltage provided to an audio amplifier in response to this energy level. ## Claims ### Claim 1 A smart speaker comprising: a processing system comprising at least one digital signal processor configured to decode an encoded audio file to produce an audio bitstream; at least one digital to analog converter coupled to the at least one digital signal processor and configured to convert the audio bitstream to an analog audio signal; at least one audio amplifier coupled to the at least one digital to analog converter and configured to amplify the analog audio signal; an audio power supply configured to receive an input voltage and provide an output voltage powering the at least one audio amplifier; and an audio power supply controller coupled to the at least one digital signal processor or the at least one digital to analog converter and configured to: identify an increased or a decreased energy requirement in an upcoming portion of the audio signal; responsive to an increased energy requirement in an upcoming portion of the audio signal, increase a power supply voltage supplied to the at least one audio amplifier and increase a look ahead time period before the increased energy requirement; and responsive to a decreased energy requirement in an upcoming portion of the audio signal, decease the power supply voltage supplied to the at least one audio amplifier. ### Claim 2 (depends on 1) The smart speaker of claim 1 wherein decreasing a power supply voltage supplied to the at least one audio amplifier responsive to a decreased energy requirement in an upcoming portion of the audio signal comprises beginning the decreasing a delay time period after the decreased energy requirement. ### Claim 3 (depends on 1) The smart speaker of claim 1 wherein the audio power supply controller receives an audio bitstream from the at least one digital signal processor. ### Claim 4 (depends on 3) The smart speaker of claim 3 wherein the audio power supply controller receives the audio bitstream from a prediction digital signal processor separate from an audio digital signal processor used to decode the encoded audio file. ### Claim 5 (depends on 1) The smart speaker of claim 1 wherein the audio power supply controller receives an audio signal from the at least one digital to analog converter. ### Claim 6 (depends on 5) The smart speaker of claim 5 wherein the audio power supply controller receives the audio signal from a digital to analog converter separate from the digital to analog converter used to produce the audio signal for the at least one audio amplifiers. ### Claim 7 A method of controlling a power supply voltage supplied to an audio amplifier, the method comprising: identifying an increased or a decreased energy requirement in an upcoming portion of an audio signal; responsive to an increased energy requirement in an upcoming portion of the audio signal, increasing a power supply voltage supplied to at least one audio amplifier and increasing a look ahead time period before the increased energy requirement; and responsive to a decreased energy requirement in an upcoming portion of the audio signal, decreasing the power supply voltage supplied to the at least one audio amplifier. ### Claim 8 (depends on 7) The method of claim 7 wherein decreasing a power supply voltage supplied to the at least one audio amplifier responsive to a decreased energy requirement in an upcoming portion of the audio signal comprises beginning the decreasing a delay time period after the decreased energy requirement. ### Claim 9 A smart speaker comprising: a processing system comprising at least one digital signal processor configured to decode an encoded audio file to produce an audio bitstream; at least one digital to analog converter coupled to the at least one digital signal processor and configured to convert the audio bitstream to an analog audio signal; at least one audio amplifier coupled to the at least one digital to analog converter and configured to amplify the analog audio signal; an audio power supply configured to receive an input voltage and provide an output voltage powering the at least one audio amplifier; and an audio power supply controller coupled to the at least one digital signal processor or the at least one digital to analog converter and configured to: identify an increased or a decreased energy requirement in an upcoming portion of the audio signal; responsive to an increased energy requirement in an upcoming portion of the audio signal, increase a power supply voltage supplied to the at least one audio amplifier; and responsive to a decreased energy requirement in an upcoming portion of the audio signal, decease the power supply voltage supplied to the at least one audio amplifier and decrease a delay time period after the decreased energy requirement. ### Claim 10 (depends on 9) The smart speaker of claim 9 wherein increasing a power supply voltage supplied to the at least one audio amplifier responsive to an increased energy requirement in an upcoming portion of the audio signal comprises beginning the increasing a look ahead time period before the increased energy requirement. ### Claim 11 (depends on 9) The smart speaker of claim 9 wherein the audio power supply controller receives an audio bitstream from the at least one digital signal processor. ### Claim 12 (depends on 11) The smart speaker of claim 11 wherein the audio power supply controller receives the audio bitstream from a prediction digital signal processor separate from an audio digital signal processor used to decode the encoded audio file. ### Claim 13 (depends on 9) The smart speaker of claim 9 wherein the audio power supply controller receives an audio signal from the at least one digital to analog converter. ### Claim 14 (depends on 13) The smart speaker of claim 13 wherein the audio power supply controller receives the audio signal from a digital to analog converter separate from a digital to analog converter used to produce the audio signal for the one or more audio amplifiers. ### Claim 15 A method of controlling a power supply voltage supplied to an audio amplifier, the method comprising: identifying an increased or a decreased energy requirement in an upcoming portion of an audio signal; responsive to an increased energy requirement in an upcoming portion of the audio signal, increasing a power supply voltage supplied to at least one audio amplifier; and responsive to a decreased energy requirement in an upcoming portion of the audio signal, decreasing the power supply voltage supplied to the at least one audio amplifier and decreasing a delay time period after the decreased energy requirement. ### Claim 16 (depends on 15) The method of claim 15 wherein increasing a power supply voltage supplied to the at least one audio amplifier responsive to an increased energy requirement in an upcoming portion of the audio signal comprises beginning the increasing a look ahead time period before the increased energy requirement. ### Claim 17 A smart speaker comprising: circuitry that decodes an encoded audio file to produce an audio bitstream and converts the audio bitstream to an analog audio signal; at least one audio amplifier that amplifies the analog audio signal; an audio power supply that receives an input voltage and provides an output voltage that powers the at least one audio amplifier; and an audio power supply controller comprising circuitry that: identifies at least one of an increased energy requirement or a decreased energy requirement in an upcoming portion of the audio signal; responsive to identifying an increased energy requirement in an upcoming portion of the audio signal, increases a power supply voltage supplied to the at least one audio amplifier and increases a look ahead time period before the increased energy requirement at which the audio power supply controller identifies the increased energy requirement; or responsive to a identifying a decreased energy requirement in an upcoming portion of the audio signal, deceases the power supply voltage supplied to the at least one audio amplifier and decreases a delay time period after the decreased energy requirement at which the audio power supply controller decreases the power supply voltage supplied to the at least one audio amplifier. ### Claim 18 A method of controlling a power supply voltage supplied to an audio amplifier, the method comprising: identifying at least one of an increased or a decreased energy requirement in an upcoming portion of an audio signal; responsive to an increased energy requirement in an upcoming portion of the audio signal, increasing a power supply voltage supplied to at least one audio amplifier and increasing a look ahead time period before the increased energy requirement at which the audio power supply controller identifies the increased energy requirement; and responsive to a decreased energy requirement in an upcoming portion of the audio signal, decreasing the power supply voltage supplied to the at least one audio amplifier and decreasing a delay time period after the decreased energy requirement at which the audio power supply controller decreases the power supply voltage supplied to the at least one audio amplifier.