Analog to digital converters with integral sample rate conversion and systems and methods using the same
AssigneeCirrus Logic, Inc.
InventorsAnand Venkitachalam, Joe Welser, Manoj Soman, Krishnan Subramoniam
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Abstract
An integrated analog to digital and sample rate converter 206 includes sampling circuitry 207 for receiving an analog signal and generating a single or multibit stream of digital signals at a first rate. A leaky integrator filter 208 removes quantization noise from the stream of samples such that resampling can be carried out. Circuitry 209/210 resamples the filtered stream of samples output from leaky integrator filter 208 to generate an output stream of samples at a second rate.
Claims21
An integrated analog to digital and sample rate converter comprising:
- sampling circuitry for receiving an analog signal and generating a stream of digital samples at a first rate;
- a leaky integrator filter for removing quantization noise from said stream of samples;
- and
- circuitry for resampling a filtered stream of samples output from said leaky integrator filter to generate an output stream of samples at a second rate.
An analog to digital converter with integral sample rate conversion comprising:
- a delta-sigma modulator for sampling an input analog signal and generating a stream of 1-bit digital samples at a first sampling rate;
- a low pass leaky integrator filter for filtering quantization noise from said stream of 1-bit digital samples;
- and
- a digital filter and associated resampler circuitry for generating a stream of multiple-bit digital samples at a second sampling rate.
A method for converting an analog signal to a stream of digital samples at a selected sampling rate comprising the step of:
- sampling the analog signal to produce a stream of samples at a first sampling rate;
- filtering the stream of samples at the first sampling rate with a leaky integrator filter to remove quantization noise;
- and
- resampling a filtered stream of samples output from the leaky integrator filter to produce a stream of samples at the selected sampling rate.
Dependencies are inferred from the claim text.