Delta-Sigma Modulator Overload Protection via Coefficient Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Delta-sigma analog-to-digital converters (ADCs) face instability and downtime when handling overload conditions, as they often become unstable when input signals exceed their full-scale range, leading to inefficiencies and noise introduction in existing overload protection mechanisms.
Innovation Solution
An overload detector is embedded within the delta-sigma modulator to detect overload conditions, allowing for real-time adjustment of internal coefficients, such as DAC current gain, to maintain stability and dynamic range without resetting the modulator, thereby preventing instability and noise introduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If delta-sigma modulator operates beyond full-scale range, then dynamic range is extended, but stability deteriorates and modulator becomes unstable
Solution Approach 1:
The patent implements dynamic coefficient adjustment where the modulator coefficients are changed in real-time based on the detected overload condition. The coefficient adjustment is controlled by the overload detector output, allowing the modulator to adapt its characteristics dynamically to handle input signals beyond the normal full-scale range while maintaining stability.
Solution Approach 2:
The patent changes the operational parameters of the modulator by adjusting coefficients in response to detected overload conditions. This parameter change allows the modulator to accommodate overloaded inputs by modifying its transfer characteristics, effectively extending the usable input range while preventing instability.
2Stability of the object's composition
If reset mechanism is used for overload protection, then stability is restored, but operational continuity deteriorates and downtime increases
Solution Approach 1:
The patent employs feedback through an overload detector that continuously monitors the modulator operation and provides control signals for coefficient adjustment. This closed-loop feedback mechanism enables automatic adaptation to overload conditions without requiring system reset, thereby maintaining continuous operation and eliminating downtime associated with traditional reset-based protection.
Solution Approach 2:
The modulator performs self-protection against overload conditions by automatically adjusting its own coefficients based on detector feedback. This self-service capability eliminates the need for external reset mechanisms and maintains operational continuity by handling overload conditions autonomously without interruption.
3Reliability
If traditional overload protection is added, then overload handling is improved, but device complexity increases and noise is introduced
Solution Approach 1:
The patent merges the overload detection and coefficient control functions directly into the modulator structure. By integrating these functions rather than adding separate external protection circuits, the implementation achieves improved overload handling while minimizing the increase in device complexity. The detector and coefficient adjustment are embedded within the existing modulator architecture.
Data Source
AI summary
Delta-sigma modulators do not handle overload well, and often become unstable if the input goes beyond the full-scale range of the modulator. To provide overload protection, an improved technique embeds an overload detector in the delta sigma modulator. When an overload condition is detected, coefficient(s) of the delta sigma modulator is adjusted to accommodate for the overloaded input. The improved technique advantageously allows the delta sigma modulator to handle overload gracefully without reset, and offers greater dynamic range at reduced resolution. Furthermore, the coefficient(s) of the delta sigma modulator can be adjusted in such a way to ensure the noise transfer function is not affected.