# US 2014/0192989 A1 · Programmably configured switchmode audio amplifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192989 A1 - Document ID: US20140192989A1 - Status: Published application - Kind: A1 - Application number: 13/777,975 - Filed: 2013-02-26 - Published: 2014-07-10 - Earliest claimed: 2013-01-09 - Assignees: QSC Audio Products, Inc. - Applicants: QSC Audio Products, LLC - Inventors: Patrick H. Quilter; Manny Rodriguez - Web page: https://patentgrep.com/patent/US20140192989A1 ## CPC - H03F 3/68: Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics {(power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602)} - H03F 1/0277: {Selecting one or more amplifiers from a plurality of amplifiers} - H03F 3/183: with semiconductor devices only - H03F 3/187: in integrated circuits - H03F 3/2173: {of the bridge type} - H03F 3/2178: {using more than one switch or switching amplifier in parallel or in series (H03F3/2173, H03F3/2175 take precedence)} - H03F 3/72: Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal - H04R 3/12: for distributing signals to two or more loudspeakers {(specially adapted for hearing aids H04R25/407)} - H04R 5/04: Circuit arrangements, {e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments (combinations of amplifiers H03F3/68; stereophonic systems H04S)} - 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 2420/01: Input selection or mixing for amplifiers or loudspeakers - H03F: AMPLIFIERS - 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 multi-channel switchmode audio amplifier is configured by a programmed processor such that each channel drives separate loads, is connected in parallel or is configured in a bridge-tied mode as well as combinations thereof. In one embodiment, amplifier channels that are connected in parallel have power amplifiers that are driven with signals from a single modulator. A feedback circuit and error amplifier from one channel controls the modulated signal that is applied to each parallely connected amplifier channel. Current feedback circuits for parallely connected amplifier channels are eliminated by tightly controlling the timing of switching in the power amplifier output stages. ## Claims ### Claim 1 A multi-channel amplifier, comprising: a number of amplifier channels for driving speaker loads; a programmed processor that is configured to: receive input from a user regarding specifications of a number of speakers to be driven by the amplifier; determine a configuration of the amplifier such that each channel drives a speaker load, is connected in parallel with another channel to drive a speaker load or drives a speaker load in a bridge-tied load configuration; and configure one or more channels in the amplifier so that the amplifier has the determined configuration to drive the desired speaker load. ### Claim 2 (depends on 1) The amplifier of claim 1, wherein the programmed processor is configured to provide instructions to the user indicating how one or more speakers are to be connected to the multi-channel amplifier. ### Claim 3 (depends on 1) The amplifier of claim 1, wherein the programmed processor is configured to search a database for speaker specifications based on input received from a user. ### Claim 4 (depends on 1) The amplifier of claim 1, wherein the specifications in the database for each speaker include its impedance and power rating. ### Claim 5 A multi-channel switchmode audio amplifier, comprising: a number of amplifier channels, each including a modulator and a power amplifier stage having switches and gate drivers; a programmed processor that is configured to connect an output of a single modulator in an amplifier channel to inputs of two or more power amplifier stages such that switching differences between the parallely connected power amplifier stages is controlled to within 100 nano seconds. ### Claim 6 A multi-channel switchmode audio amplifier, comprising a number of channels; each including a modulator, a switching power amplifier stage and a feedback circuit; and a programmed processor that is configured to connect two more channels in parallel by connecting an output of a modulator from a master channel to an input of the power amplifier stage for one or more parallely connected slave channels; and for disconnecting the feedback circuit of each slave channel such that current sharing between the master and slave channels is controlled based on limiting differences in switching in the power amplifier stages of the parallely connected master and slave channels to within 100 nano seconds.