Distortion reducing variable output impedance class-D amplifier
AssigneeCirrus Logic, Inc.
InventorsZhaohui He, Ruoxin Jiang, Rahul Singh
Life of this patent
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Abstract
A Class-D amplifier that includes a driver stage operable in a plurality of modes having different respective output impedances, a loop filter having an output, and a circuit configured to sense a current at a load of the Class-D amplifier, determine, based on the sensed current, an IR drop for a respective output impedance of the driver stage, and add the IR drop to the loop filter output to compensate for the respective output impedance of the driver stage to reduce distortion.
Claims16
A method for reducing distortion in a Class-D amplifier that has a driver stage operable in a plurality of modes having different respective output impedances, comprising:
- sensing a current at a load of the Class-D amplifier;
- determining, based on the sensed current, an IR drop for a respective output impedance of the driver stage;
- and
- adding the IR drop to a loop filter output of the Class-D amplifier to compensate for the respective output impedance of the driver stage.
A Class-D amplifier, comprising:
- a driver stage operable in a plurality of modes having different respective output impedances;
- a loop filter having an output;
- and
- a circuit configured to:
- sense a current at a load of the Class-D amplifier;
- determine, based on the sensed current, an IR drop for a respective output impedance of the driver stage;
- and
- add the IR drop to the loop filter output to compensate for the respective output impedance of the driver stage to reduce distortion.
Dependencies are inferred from the claim text.