Controlling noise transfer function of signal path to reduce charge pump noise
AssigneeCirrus Logic, Inc.
InventorsPradeep Dhananjay, Tejasvi Das, Bhupendra Manola, Bruce E. Duewer
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Abstract
An apparatus may include a delta-sigma modulator for quantization noise shaping of a digital signal, a digital-to-analog converter configured to generate an analog signal from the digital signal, and an amplifier configured to amplify the analog signal and powered from a charge pump, wherein the charge pump is configured to operate at a switching frequency approximately equal to a zero of a modulator noise transfer function of the delta-sigma modulator, such that the impact of charge pump noise on a total harmonic distortion noise of the apparatus is minimized.
Claims6
An apparatus comprising:
- a delta-sigma modulator for quantization noise shaping of a digital signal;
- a digital-to-analog converter configured to generate an analog signal from the digital signal;
- and
- an amplifier configured to amplify the analog signal and powered from a charge pump, wherein the charge pump is configured to operate at a switching frequency approximately equal to that of a zero of a modulator noise transfer function of the delta-sigma modulator, such that the impact of charge pump noise on a total harmonic distortion noise of the apparatus is minimized.
A method for minimizing noise in an apparatus comprising a delta-sigma modulator for quantization noise shaping of a digital signal, a digital-to-analog converter configured to generate an analog signal from the digital signal, and an amplifier configured to amplify the analog signal and powered from a charge pump, the method comprising:
- operating the charge pump at a switching frequency approximately equal to that of a zero of a modulator noise transfer function of the delta-sigma modulator, such that the impact of charge pump noise on a total harmonic distortion noise of the apparatus is minimized.
Dependencies are inferred from the claim text.