Audio amplifer with fast wake-up power supply

An audio amplifier comprising:

• a power amplifier configured to amplify an input audio signal to obtain an amplified audio signal and output the amplified audio signal to a speaker;
• an isolated power supply comprising one or more capacitors and a burst mode input configured to receive a burst mode signal, wherein the burst mode signal indicates whether the audio amplifier is in a standby state, wherein, when the burst mode signal indicates that the audio amplifier is in the standby state, the isolated power supply cycles between an active state for a first segment of a time period and an inactive state for a second segment of the time period, and wherein the one or more capacitors of the isolated power supply are charged when the isolated power supply is in the active state;
• a burst generator configured to generate the burst mode signal in response to a control signal and to provide the burst mode signal to the burst mode input;
• and
• a controller configured to generate the control signal based on a determination that the audio amplifier is in the standby state, wherein the first segment of the time period is at least an order of magnitude less than the second segment of the time period.

A method of controlling an audio amplifier that supports a standby mode with fast wake-up, the method comprising:

• receiving a command to cause the audio amplifier to enter the standby mode;
• generating a control signal to enter the standby mode in response to the command;
• activating a burst generator configured to generate a burst mode signal in response to the control signal and to provide the burst mode signal to a burst mode input of an isolated power supply;
• and
• in response to the isolated power supply receiving the burst mode signal, activating the isolated power supply for a first segment of a time period and deactivating the isolated power supply for a second segment of the time period, wherein activating the isolated power supply for the first segment of the time period comprises charging one or more capacitors of the isolated power supply, wherein the first segment of the time period is substantially shorter than the second segment of the time period.

An audio system comprising:

• a speaker configured to output audio based on an audio signal;
• and
• an audio amplifier in communication with the speaker and configured to provide the audio signal to the speaker for output as the audio, wherein the audio amplifier comprises:
• a power amplifier configured to amplify an input audio signal to obtain the audio provided to the speaker for output;
• an isolated power supply configured to power the power amplifier and comprising one or more capacitors and a burst mode input configured to receive a burst mode signal, wherein the burst mode signal indicates whether the audio amplifier is in a standby state, wherein, when the burst mode signal indicates that the audio amplifier is in the standby state, the isolated power supply cycles between an active state for a first segment of a time period and an inactive state for a second segment of the time period, and wherein the one or more capacitors of the isolated power supply are charged when the isolated power supply is in the active state;
• a burst generator configured to generate the burst mode signal in response to a control signal and to provide the burst mode signal to the burst mode input;
• and
• a controller configured to generate the control signal based on a determination that the audio amplifier is in the standby state, wherein the first segment of the time period is at least an order of magnitude less than the second segment of the time period.