Sigma-Delta ADC Coefficient Tuning for Noise and Loop-Delay Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sigma-delta modulated analog-to-digital converters face performance degradation due to noise, component variations, and circuit non-linearities, which affect signal quality and accuracy.
Innovation Solution
Incorporating an enhanced integrator with changeable coefficients and a loop-delay compensation circuit, both controlled by a processor, to adjust and compensate for noise, non-linearities, and component variations, thereby improving signal-to-noise-plus-distortion ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sigma-delta modulator uses over-sampling and filtering to achieve high resolution, then signal-to-noise-plus-distortion ratio is improved, but the converter becomes sensitive to circuit noise and timing variations
Solution Approach 1:
The patent implements changeable coefficients in the integrator and loop-delay compensation circuit that can be dynamically adjusted based on operating conditions. This allows the converter to optimize its performance parameters to compensate for circuit noise and timing variations while maintaining high signal-to-noise-plus-distortion ratio.
Solution Approach 2:
The patent employs a feedback mechanism where the processor monitors the converter performance and automatically adjusts the integrator coefficient and loop-delay compensation coefficient. This closed-loop control compensates for circuit noise and timing variations by adapting the system parameters in real-time based on actual performance metrics.
2Measurement precision
If feedback technique is used to provide error correction capability, then accuracy is improved, but loop delay caused by circuit non-linearities decreases performance
Solution Approach 1:
The patent implements a loop-delay compensation circuit that proactively compensates for delay effects before they significantly impact performance. By predicting and compensating for loop delay in advance, the system maintains accuracy while minimizing the performance-degrading effects of timing delays.
Solution Approach 2:
The loop-delay compensation circuit acts as an intermediary element that mediates between the feedback path and the integrator. This intermediate stage compensates for the delay introduced by circuit non-linearities, allowing the feedback mechanism to maintain accuracy without being degraded by timing issues.
3Adaptability or versatility
If integrator coefficient is increased to handle escalated input signals, then dynamic range is improved, but signal distortion increases due to clipping
Solution Approach 1:
The patent implements a dynamic coefficient adjustment mechanism where the integrator coefficient is not fixed but can be changed in response to input signal conditions. This allows the system to maintain optimal dynamic range while preventing clipping-induced distortion by adapting the coefficient to match the actual signal amplitude and characteristics.
Solution Approach 2:
The processor automatically monitors the integrator output and adjusts the integrator coefficient without external intervention. This self-service mechanism prevents signal distortion by detecting clipping conditions and automatically adjusting the coefficient to maintain optimal operation, thereby eliminating the need for external manual adjustment.
4Ease of manufacture
If component variations are present in the circuit, then manufacturing cost is reduced, but noise and performance decrease
Solution Approach 1:
The patent uses changeable coefficients that can be programmed to compensate for component variations. Instead of requiring precision-matched components, the system adapts its operational parameters to account for manufacturing tolerances, thereby maintaining low noise performance while using cost-effective standard components.
Solution Approach 2:
The automatic coefficient adjustment mechanism provides feedback compensation for component variations. By monitoring performance and adjusting the integrator and loop-delay coefficients, the system compensates for noise introduced by component variations, maintaining performance without requiring expensive precision components.
Data Source
AI summary
A sigma-delta modulated analog-to-digital converter having an integrator with a first changeable coefficient and/or having an excess loop-delay circuit also having a second changeable coefficient. The changeable coefficients enable the converter to account for noise mixed with the input signal, circuit non-linearities, and component variations.