Systems and methods of reduced distortion in a class D amplifier
AssigneeTexas Instruments Incorporated
InventorRichard Knight Hester
Life of this patent
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Abstract
Systems and methods for reduced distortion in a class D amplifier are provided. An “ideal” digital output signal is produced. The “ideal” digital output signal is then compared to the actual output signal in an error amplifier. The integrator input is the difference between the output stage waveform and the ideal output stage waveform. The net input to the integrator now comprises the imperfections of the power stage, and the feedback loop drives their average to zero. This error is then amplified and integrated. The integrated signal is than applied to a summer where it is added to the analog input. Then as in the typical Class D amplifier, the integrated signal is compared in an error amplifier to a ramp signal generated from the ramp generator.
Claims19
An amplifier comprising:
- a signal source configured to produce a ramp signal;
- a first comparator configured to digitize a difference between an input signal and the ramp signal;
- a first integrator configured to integrate a difference between an output of the first comparator and an output of a power amplifier;
- a first error amplifier configured to amplify a difference between the integrated signal and the input signal;
- and
- a second comparator configured to digitize a difference between an output of the first error amplifier and the ramp signal.
A class D amplifier comprising:
- a first integrator configured to integrate an ideal output signal and a real output signal;
- and
- a second integrator configured to integrate the ideal output signal, an output of the first integrator and the real output signal.
A method of amplification comprising:
- integrating an ideal amplifier output signal and a real amplifier output signal;
- combining the integrated signal with an input signal to produce a combined signal;
- and
- comparing the combined signal with a ramp signal.
Dependencies are inferred from the claim text.