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US 2026/0238169 A1Published application
Class-d amplifier with nested feedback loops
AssigneeQsc, LLC
InventorAnders Lind
Life of this patent
Estimating the term…
Abstract
A class-D amplifier with multiple “nested” levels of feedback. The class-D amplifier surrounds an inner feedback loop, which takes the output of a switching amplifier and corrects for errors generated across the switching amplifier, with additional feedback loops that also take the output of the switching amplifier.
Claims20
A method of generating an amplified audio output signal via an audio amplifier, comprising:
- receiving an audio input signal to the audio amplifier, wherein the audio amplifier comprises a first summing node, a second summing node, a third summing node, a switch node, a switching amplifier coupled between the switch node and the first summing node, and a filter coupled to the switch node, wherein the filter is between the switch node and a speaker that receives the amplified audio output signal;
- receiving via a global feedback loop of the amplifier a signal portion, wherein the signal portion is received from the filter and provided to the third summing node;
- generating via a nested amplifier portion of the amplifier a modulated signal driven on the first summing node, wherein the nested amplifier portion comprises a first feedback loop nested within a second feedback loop, wherein:
- the first feedback loop comprises a first loop feedback module between the switch node and the first summing node, and
- the second feedback loop comprises:
- a second loop feedback module coupled between the switch node and the second summing node;
- a second loop integrator module coupled to the second summing node;
- a second loop compensator module coupled to the second loop integrator module and a compensator node, with the second loop integrator module between the second loop compensator module and the compensator node;
- and
- a second loop forward compensator module coupled between the second loop compensator module and the first summing node;
- providing via the first loop feedback module a first feedback signal from the switch node to the first summing node;
- and
- providing via the second feedback loop a second feedback signal from the switch node to the second summing node.
10 more elements
A method of generating an amplified audio output signal via an audio amplifier, comprising:
- receiving an audio input signal to the audio amplifier, wherein the audio amplifier comprises first and second summing nodes, a switch node, a switching amplifier coupled to the switch node and the first summing node, and a filter coupled to the switch node, wherein the filter is between the switch node and a speaker that receives the amplified audio output signal;
- generating via a nested amplifier portion an amplified signal portion on the first summing node, wherein the nested amplifier portion comprises a first feedback loop nested within second feedback loop, wherein:
- the first feedback loop comprises a first loop feedback module, and
- the second feedback loop comprises:
- a second loop feedback module coupled between the switch node and the second summing node;
- a second loop integrator module coupled to the second summing node;
- and
- a second loop compensator module coupled to the second loop integrator module and a compensator node, with the second loop integrator module between the second loop compensator module and the compensator node;
- providing via the first loop feedback module a first feedback signal portion from the switch node to the first summing node;
- and
- providing via the second feedback loop a second feedback signal portion from the switch node to the second summing node.
8 more elements
A method of generating an amplified audio output signal via a Class-D amplifier, comprising:
- receiving via the Class-D amplifier an audio input signal, wherein the Class-D amplifier has a switching amplifier, a switch node, a first summing node, an inductor/capacitor (LC) filter coupled to the switch node, a global feedback loop, and nested feedback circuits that include a first feedback loop nested within second feedback loop, wherein the global feedback loop is coupled to the LC filter output, the input signal, and a global summing node;
- nested feedback circuits configured to generate the modulated signal driven on the first summing node, based on the input signal, the nested feedback circuits comprising a first feedback loop nested within second feedback loop, wherein;
- driving via the switching amplifier an amplified signal to the switch node based on a modulated signal received by the switching amplifier at the first summing node;
- generating via the inductor/capacitor (LC) filter an amplifier output signal from the amplified signal driven by the switching amplifier;
- generating via nested feedback circuits the modulated signal driven on the first summing node, based on the input signal, wherein the nested feedback circuits comprise a first feedback loop nested within second feedback loop,
- wherein the first feedback loop comprises a first loop feedback module from the switch node to the first summing node;
- and
- wherein the second feedback loop comprises:
- a second loop feedback module coupled to the switch node and a second summing node;
- a second loop integrator module coupled to the second summing node and an integrator node;
- a second loop compensator module coupled to the integrator node and a compensator node;
- and
- a second loop forward compensator module coupled to the compensator node and the first summing node.
10 more elements
Dependencies are inferred from the claim text.