ADC Signal Path Crossfading to Prevent Clipping Artifacts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for analog-to-digital conversion in digital microphony face challenges with precise matching of signal components to prevent clipping, especially in portable applications where high-resolution converters are costly and power-intensive, and nonlinear networks introduce noise and distortion.
Innovation Solution
The method involves weighting and merging digitized signal components with a variable weighting factor to smoothly crossfade between signal paths, adapting to changing signal conditions and preventing clipping, using the signal magnitude as a reference parameter and incorporating a time-delayed adjustment to ensure seamless transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If two low-resolution converters are used instead of one high-resolution converter, then power consumption is reduced and cost is decreased, but precise matching of signal components becomes extremely difficult and complex
Solution Approach 1:
The patent applies dynamics by making the weighting factor variable rather than fixed. The weighting factor adapts dynamically based on the signal level in the first signal pathway, automatically adjusting the contribution of each signal pathway to maintain optimal signal quality while avoiding clipping. This dynamic adaptation eliminates the need for extremely precise static matching between pathways.
Solution Approach 2:
The patent changes the parameter of the weighting factor from a fixed value to a variable that depends on signal characteristics. By monitoring the signal level in the first pathway and adjusting the weighting factor accordingly, the system transitions between different operating modes smoothly, resolving the matching complexity issue through parameter adaptation.
2Reliability
If switching between signal pathways occurs to avoid clipping, then the dynamic range is maintained, but time shifts and phase relations cause unwanted interferences at junctions
Solution Approach 1:
The patent ensures continuity of useful action by using smooth crossfading instead of abrupt switching between signal pathways. The weighting factor transitions continuously based on signal level, ensuring that both pathways contribute smoothly to the output signal. This continuous adaptation eliminates discontinuities, phase relation issues, and interference artifacts that would occur with abrupt switching.
3Reliability
If gain staging with different amplification levels is used, then the dynamic range for transmission is maximized, but the effort for matching signal components increases without simplifying the actual A/D conversion
Solution Approach 1:
The system performs self-service by automatically adjusting the weighting factor based on the signal level in the first pathway. The matching and weighting are performed autonomously without requiring external intervention or complex manual calibration, allowing the system to maintain optimal dynamic range adaptation while minimizing matching effort through self-regulation.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for converting an analog input signal into a digital output signal, where at least two analog signal components which differ in signal level are derived from the input signal, and the respective signal components are subjected to an analog-digital conversion, characterized by the fact that the digitized signal components are weighted with a variable weighting factor and the weighted signal components are added to each other.