# US 9,438,183 B2 · Amplifier device and method for activating an amplifier device or the amplifier unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,183 B2 - Document ID: US9438183B2 - Status: Granted - Kind: B2 - Application number: 14/371,885 - Filed: 2013-01-14 - Published: 2014-12-11 - Granted: 2016-09-06 - Earliest claimed: 2012-01-16 - Assignees: Robert Bosch GmbH - Applicants: Robert Bosch GmbH - Inventors: Fabian Hoffmeister - Web page: https://patentgrep.com/patent/US9438183B2 ## CPC - H03F 3/185: with field-effect devices (H03F3/187 takes precedence) - H03F 1/305: {in case of switching on or off of a power supply} - H03F 3/2171: {with field-effect devices (H03F3/2173 - H03F3/2178 take precedence)} - H03F 3/2178: {using more than one switch or switching amplifier in parallel or in series (H03F3/2173, H03F3/2175 take precedence)} - H03F 2200/03: the amplifier being designed for audio applications - H03F 2203/21157: A filter circuit being added at the output of a power amplifier stage - H03F 2203/21178: Power transistors are made by coupling a plurality of single transistors in parallel - H03F: AMPLIFIERS ## Abstract Known types of amplifiers include so-called class D amplifiers, which first use a pulse-width modulator to convert an analog signal into a pulse-width modulated switching signal, which is then amplified and subsequently converted back into a continuously variable voltage via a filter. This type of amplifier is particularly energy-efficient and is therefore preferably used for high-power amplifiers. The invention relates to an amplifier device 1 comprising a control device (5), wherein the control device (5) has an input interface for an audio signal (2), and comprising an amplifier unit (9) for amplifying the audio signal (2, 8) downstream of the control device (5), wherein the control device (5) has a delay module (6) that is designed to transmit the audio signal (2), delayed by a delay value delta_t, to the amplifier unit (9) and to automatically and/or autonomously reduce the delay value delta_t from a starting value delta_t to a final value during an adaptation phase AP. ## Claims ### Claim 1 An amplifier comprising: an amplifier unit, and a control device including an input interface for an audio signal, a delay module designed to transmit the audio signal, delayed by a delay value, to the amplifier unit and to reduce the delay value from a starting value to a final value during an adaptation phase, and a switch-on module for activating the amplifier unit and the delay module in response to an incoming audio signal at the input interface when the amplifier unit is in an energy saving mode, wherein the starting value for the delay of the audio signal is selected to be equally long as or longer than the duration of an activation process of the amplifier unit so that the delayed audio signal is provided to the amplifier unit after the amplifier unit is activated and capable of providing an output. ### Claim 2 (depends on 1) The amplifier according to claim 1, wherein the starting value is selected to be less than 80 ms. ### Claim 3 (depends on 1) The amplifier according to claim 1, wherein the final value is less than 50% of the starting value or is 0 s. ### Claim 4 (depends on 1) The amplifier according to claim 1, wherein the transformation of the delay value from the starting value to the final value takes place in the adaptation phase for a period of time greater than 1 s and for a period of time less than 40 s. ### Claim 5 (depends on 1) The amplifier according to claim 1, wherein the amplifier unit comprises a class D amplifier. ### Claim 6 (depends on 5) The amplifier according to claim 5, wherein the class D amplifier can be switched to an energy saving mode. ### Claim 7 (depends on 5) The amplifier according to claim 5, wherein a switch is disposed downstream of the output of the class D amplifier, said switch being designed to separate the output of the class D amplifier from a downstream loud speaker in the energy saving mode, so that no noise interferences are transmitted from the class D amplifier to the loud speaker during the activation process. ### Claim 8 (depends on 1) The amplifier according to claim 1, wherein the control device includes a digital signal processor (DSP) that is designed to cache the audio signal during the delay. ### Claim 9 A method for activating an amplifier, the method comprising: activating the amplifier from an energy saving mode in response to an incoming audio signal, delaying the audio signal by a delay value during an activation process of the amplifier, amplifying the delayed audio signal with a starting value as the delay value after the activation process, and reducing the delay value from a starting value to a smaller value and eventually to zero during an adaptation phase so that the audio signal is amplified in an undelayed manner after the adaptation phase. ### Claim 10 A control device, comprising: an input interface for an audio signal, an output interface for outputting the audio signal to a downstream amplifier unit for amplifying the audio signal, a delay module designed to transmit the audio signal, delayed by a delay value, to the downstream amplifier unit and to reduce the delay value from a starting value to a final value during an adaptation phase, and a switch-on module for activating the downstream amplifier unit and for activating the delay module in response to the audio signal when the downstream amplifier unit is in an energy saving mode. ### Claim 11 (depends on 10) The control device according to claim 10, wherein the delay module transmits the audio signal to the downstream amplifier unit, and automatically and/or autonomously reduces the delay value during the adaptation phase. ### Claim 12 (depends on 1) The amplifier according to claim 1, wherein the delay module transmits the audio signal to the amplifier unit, and automatically and/or autonomously reduces the delay value during the adaptation phase. ### Claim 13 (depends on 9) The method according to claim 9, wherein reducing the delay value from a starting value to a smaller value and eventually to zero includes reducing the delay value continuously during the adaptation phase, the adaptation phase occurring for between 5 seconds and 10 seconds.