System and method to enhance noise performance in a delta sigma converter
AssigneeAnalog Devices, Inc.
InventorsAbhishek Bandyopadhyay, Preston S. Birdsong, Adam R. Spirer
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Abstract
Systems and methods for improving noise efficiency in a Delta Sigma modulator. A bypass scheme for a noise splitter is disclosed that reduces toggling activity for small signals. In particular, a sample-by-sample bypass noise splitter is disclosed that includes a noise splitting module and a bypass line. The bypass line bypasses the noise splitting module when signals are below a selected threshold, increasing efficiency of the system.
Claims20
A sample-by-sample bypass noise splitter, comprising:
- a noise splitting module configured to split an input signal into a plurality of split signals, wherein each of the plurality of split signals is smaller than the input signal, wherein the noise splitting module includes a first multiplexor to process a first output;
- and
- a bypass line configured to pass the input signal directly through to an output line, wherein the bypass line includes a second multiplexor to process a second output and least significant bits of the input signal;
- wherein signals above a selected threshold are directed to the noise splitting module and wherein signals below the selected threshold are directed to the bypass line.
A converter having enhanced noise performance, comprising:
- an interpolator configured to receive an input signal;
- a noise splitter including a noise splitting module and a bypass line, configured to receive an interpolated signal and output a plurality of parallel output signals;
- a plurality of rotational scramblers coupled to the noise splitter configured to apply discrete element modeling to each of the plurality of parallel output signals and output a respective plurality of DEM output signals;
- and
- a plurality of digital-to-analog converters (DACs) coupled to the rotational scramblers configured to convert each of the plurality of DEM output signals to a respective analog signal;
- wherein the noise splitter is a sample-to-sample bypass splitter, and wherein signals above a selected threshold are directed to the noise splitting module and wherein signals below the selected threshold are directed to the bypass line.
A method for a sample-by-sample bypass noise splitter, comprising:
- receiving an input signal;
- determining whether the input signal is above a selected threshold;
- when the input signal is above the selected threshold:
- splitting the input signal into a plurality of split signals, wherein each of the plurality of split signals is smaller than the input signal, and
- processing a first output at a first multiplexor;
- and
- when the input signal is below the selected threshold:
- passing the input signal directly through to an output line, and
- processing a second output and least significant bits of the input signal at a second multiplexor.
Dependencies are inferred from the claim text.