Pipelined ADC Dither Subtraction for Faster Correlation Convergence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Convergence time of correlation algorithms used to remove dither signals from pipelined analog-to-digital converters (ADCs) is excessively long, leading to prolonged start-up and production test times due to the propagation of dither signals through multiple stages.
Innovation Solution
Reconstructing and subtracting estimates of dither signals before applying the correlation algorithm, significantly reducing the energy of undesired sequences and improving convergence time by using a subtraction method in conjunction with the correlation algorithm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a correlation algorithm is applied to remove dither signals from the output of a pipelined ADC, then the dither signals are gradually reduced and average out to zero, but the convergence time is very long leading to prolonged start-up and production test times
Solution Approach 1:
The patent applies preliminary action by performing a subtraction operation before the correlation algorithm to pre-remove a portion of the dither signal energy. Specifically, the patent subtracts the dither signal injected into a stage from the output of that stage before applying the correlation algorithm, which significantly reduces the dither signal energy that the correlation algorithm needs to process, thereby reducing convergence time while maintaining dither removal accuracy
2Adaptability or versatility
If dither signals are injected into stages of a pipelined ADC for calibration or dithering purposes, then the useful functions are achieved, but the dither signals propagate through subsequent stages and influence the overall output, requiring complex correlation processing
Solution Approach 1:
The patent applies the extraction principle by removing the dither signal component from the output signal before correlation processing. The method extracts the known dither signal that was injected into a specific stage and subtracts it from the overall output, thereby isolating and removing the harmful dither propagation effect while preserving the useful signal and calibration functionality
Data Source
AI summary
A method and a corresponding device reduce the convergence time of a correlation algorithm that uses random signals injected into an analog-to-digital converter (ADC) as input to the algorithm. The method and device involve, at a processor of a pipelined ADC, injecting a random signal into each of a plurality of stages in the pipeline and obtaining digital values generated in response to the random signals. Noise components of residue signals in the plurality of stages are calculated as a function of the digital values and values of the random signals. The noise components correspond to the random signals.