Dynamic Element Matching DAC Drive for Audio Distortion Shaping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing digital-to-analog converters (DACs) introduce distortion in audio signals due to component mismatches during production, leading to undesirable artifacts like popping and clicking, which are consistent for a given input signal.
Innovation Solution
A dynamic element matching network (DEM) system with variable and fixed-width configurations dynamically adjusts the number and order of activated bit-cells based on signal strength, using shuffle networks and barrel shifters to minimize distortion by randomizing bit-cell selection and ensuring even usage over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If dynamic element matching network is used to randomize bit-cell selection, then distortion is reduced by converting predictable errors into pseudorandom noise, but device complexity increases due to additional shuffle networks and control circuits
Solution Approach 1:
The patent converts the harmful predictable distortion errors into beneficial pseudorandom noise through dynamic element matching. The DEM network randomizes bit-cell activation patterns, transforming consistent distortion artifacts into stochastic noise that can be filtered more easily, particularly in audio applications where noise is less perceptible than systematic distortion.
Solution Approach 2:
The system implements dynamic element matching by continuously varying which bit-cells are activated based on signal characteristics. The shuffle networks dynamically reconfigure bit-cell selection on a sample-by-sample basis, adapting the activation pattern to minimize distortion while maintaining the desired signal output level.
2Object-affected harmful factors
If variable-width and fixed-width DEM networks are used to dynamically adjust bit-cell activation, then audio quality is improved by minimizing audible artifacts, but manufacturing precision requirements increase due to need for precise bit-cell population control
Solution Approach 1:
The patent employs variable-width and fixed-width DEM networks that dynamically adjust the number of activated bit-cells based on signal strength and population availability. This dynamic control allows the system to adapt to varying signal conditions while maintaining optimal distortion performance across different operating ranges.
Solution Approach 2:
The DEM system is segmented into variable-width and fixed-width components, each handling different aspects of bit-cell management. The variable-width portion handles dynamic population adjustments while the fixed-width portion provides stable baseline operation, dividing the complex control function into manageable segments.
3Object-affected harmful factors
If bit-cell population is adjusted based on signal strength, then distortion mitigation effectiveness is improved, but device complexity increases due to additional calculation circuits for population management
Solution Approach 1:
The system performs preliminary calculation of the available bit-cell population based on signal strength before executing the actual DEM activation. The first calculation circuit determines the population in advance, allowing the second calculation circuit and DEM networks to operate with this pre-computed information, optimizing distortion mitigation while managing complexity through staged processing.
Solution Approach 2:
The calculation circuits serve as intermediaries between the input signal and the DEM activation process. They translate signal strength characteristics into appropriate bit-cell population levels, mediating the control signal flow and enabling sophisticated distortion management without requiring direct complex interaction between all system components.
Data Source
AI summary
This disclosure relates to a system for mitigating distortion in a signal, including a first calculation circuit configured to determine a bit-cell population available to be activated of a plurality of bit-cells based on a signal strength of an input signal, a second calculation circuit configured to determine a number of bit-cells to be activated based on the signal strength of the input signal, the number of bit-cells to be activated being less than or equal to the bit-cell population, a variable-width dynamic element matching network (“variable DEM”) configured to activate a first subset of bit-cells of the bit-cell population based on the number of bit-cells to be activated, and one or more fixed-width dynamic element matching networks (“fixed DEMs”) configured to activate a second subset of bit-cells of the bit-cell population based on the number of bit-cells to be activated.