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US 12,744,497 B2Granted
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
An audio amplifier that generates an amplified output signal, comprising:
- first and second summing nodes;
- a switch node;
- a switching amplifier coupled between the switch node and the first summing node;
- a filter coupled to the switch node, with the filter between the switch node and a speaker that receives the amplified output signal;
- a global feedback loop configured to receive a signal portion from the filter and provide the signal portion to a third summing node;
- and
- a nested amplifier portion configured to generate a modulated signal driven on the first summing node, the nested amplifier portion comprising a first feedback loop nested within the second feedback loop, wherein:
- the first feedback loop comprises:
- a first loop feedback module that provides a first feedback signal from the switch node to the first summing node;
- and
- the second feedback loop that provides a second feedback signal from the switch node to the second summing node, 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.
13 more elements
An audio amplifier, comprising:
- first and second summing nodes;
- a switch node;
- a switching amplifier coupled to the switch node and the first summing node;
- a filter coupled to the switch node, with the filter between the switch node and a speaker that receives the amplified output signal;
- a nested amplifier portion configured to generate an amplified signal portion driven on the first summing node, the nested amplifier portion comprising a first feedback loop nested within second feedback loop, wherein:
- the first feedback loop comprises:
- a first loop feedback module that provides a first feedback signal portion from the switch node to the first summing node;
- and
- the second feedback loop that provides a second feedback signal portion from the switch node to the second summing node, 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.
11 more elements
A class-D amplifier that receives an audio input signal, the amplifier comprising:
- a switching amplifier configured to drive an amplified signal to a switch node based on a modulated signal received by the switching amplifier at a first summing node;
- an inductor/capacitor (LC) filter coupled to the switch node and configured to generate an amplifier output signal from the amplified signal driven by the switching amplifier;
- a global feedback loop coupled to the LC filter output, the input signal, and a global summing node;
- and
- 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 a second feedback loop, wherein:
- the first feedback loop comprises:
- a first loop feedback module from the switch node to the first summing node;
- and
- 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.
11 more elements
Dependencies are inferred from the claim text.