State-delayed technique and system to remove tones of dynamic element matching
AssigneeBroadcom Corporation
InventorMinsheng Wang
Life of this patent
Estimating the term…
Abstract
A filter structure used with a dynamic element matching encoder for a sigma-delta digital-to-analog converter is presented. A sampled input sequence having undesired frequency tones is divided into even and odd data sub-sequences. Each of the sub-sequences is processed by a dynamic element matching encoder, with a transfer function H(z−1). The resulting processed sub-sequences are combined into an output sequence. The undesired frequency tones are substantially reduced in the output sequence.
Claims12
A method of performing dynamic element matching (DEM) on an input data stream having multiple consecutive data samples and a data sample rate equal to Fs, each data sample separated from the next by one sample period, comprising:
- a. separating the input data stream into n alternating data streams, wherein each data sample in the input data stream is consecutively input to a different alternating data stream than data samples immediately preceding and following the data sample;
- b. performing a DEM operation on each data sample within the n alternating data streams to produce shuffled data samples according to a shuffler state of each alternating data stream;
- and
- c. combining the n alternating data streams to produce a shuffled output data stream, wherein the n alternating data streams are combined in alternating order.
A method of performing dynamic element matching (DEM) on an input data stream having a data sample rate equal to Fs, the input data stream including alternating first, second, and third data samples, comprising:
- a. performing a DEM operation on every first data sample to produce a stream of shuffled first data samples;
- b. performing a DEM operation on every second data sample to produce a stream of shuffled second data samples;
- c. performing a DEM operation on every third data sample to produce a stream of shuffled third data samples;
- and
- d. combining in an alternating manner the shuffled first, second, and third data samples to produce an output data stream, wherein Fs/2 tones produced by the DEM operations of said steps (a), (b), and (c) are substantially reduced in the output data stream.
Dependencies are inferred from the claim text.