Abstract:
In an embodiment, a class-AB amplifier includes: an output stage that includes a pair of half-bridges configured to be coupled to a load; and a current sensing circuit coupled to a first half-bridge of the pair of half-bridges. The current sensing circuit includes a resistive element and is configured to sense a load current flowing through the load by: mirroring a current flowing through a first transistor of the first half-bridge to generate a mirrored current, flowing the mirrored current through the resistive element, and sensing the load current based on a voltage of the resistive element.
Abstract:
A circuit can be used in a speaker system. The circuit includes an amplifier with an output configured to be coupled to a speaker. An offset comparator has an input coupled the output of the amplifier and is configured to provide an offset control signal. A digital circuit has a first input coupled to an output of the offset comparator, a second input configured to receive an amplifier control signal, a third input configured to receive a play control signal, and an output configured to provide a forced mute signal that can be used to control the amplifier.
Abstract:
An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.
Abstract:
A digital circuit can be used in a speaker system. An intermediate node provides a speaker protection control signal. A first latch for receives an offset control signal. A first logic gate receives a play control signal, the offset control signal, and the speaker protection control signal. A second logic gate is coupled to the first latch for receiving the play control signal and the speaker protection control signal. A second latch is coupled to the first logic gate for providing a forced mute signal. A third latch is coupled to the second logic gate and to the intermediate node.
Abstract:
A clamping circuit for a class AB amplifier includes a reference voltage circuit, four NPN Darlington transistors having inputs coupled to the reference voltage circuit, and outputs for providing four clamped voltages, and a split NPN Darlington transistor having an input coupled to the reference voltage circuit, and four separate outputs for providing four AC ground voltages.
Abstract:
An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.
Abstract:
An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.
Abstract:
An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.
Abstract:
An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.
Abstract:
A clamping circuit for a class AB amplifier includes a reference voltage circuit, four NPN Darlington transistors having inputs coupled to the reference voltage circuit, and outputs for providing four clamped voltages and a split NPN Darlington transistor having an input coupled to the reference voltage circuit, and four separate outputs for providing four AC ground voltages.