Squelch Detection Circuit With Adaptive Common-Mode Thresholding
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Solution Overview
Problem
Conventional squelch detectors face challenges in differentiating between valid signals and noise in low-power environments with significant process variation and high input common mode variation, making it difficult to function effectively.
Innovation Solution
A squelch detector that adapts by averaging and shifting the common mode of input signals and threshold voltages, allowing dynamic adjustment of referential threshold voltages based on environmental conditions, enabling effective differentiation between valid signals and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional squelch detector is used in low-power environments, then power consumption is reduced, but the ability to differentiate between valid signal and noise deteriorates due to process variation and input common mode variation
Solution Approach 1:
The patent dynamically adjusts the common mode voltage level of the referential threshold voltages to track and compensate for input common mode variations. By changing the parameter (common mode voltage) based on environmental conditions, the detector maintains its ability to differentiate signals from noise even in low-power environments with process variation
Solution Approach 2:
The squelch detector implements a feedback mechanism where the common mode of input signals is averaged with the common mode of static referential threshold voltages, and this average is used to shift both threshold voltages and input signals. This closed-loop feedback compensates for process variation and maintains detection accuracy without increasing power consumption
2Device complexity
If static referential threshold voltages are used, then device complexity is reduced, but adaptability to environmental conditions and process variation deteriorates
Solution Approach 1:
The system performs self-adjustment by automatically averaging the common mode of input signals with the common mode of threshold voltages and using this average to shift both. This self-service mechanism adapts to environmental conditions without requiring external calibration or complex control circuits
Solution Approach 2:
The patent transforms static referential threshold voltages into dynamic thresholds that automatically adjust to track input signal behavior. The common mode shifting mechanism makes the threshold voltages adaptive to environmental conditions while maintaining relatively simple circuit implementation
3Measurement precision
If common mode shifting is implemented to track input signal behavior, then signal differentiation accuracy is improved, but device complexity increases due to additional circuitry for averaging and shifting
Solution Approach 1:
The patent combines the threshold voltage generation and common mode adjustment functions into a unified mechanism. The same circuit that generates referential threshold voltages also performs common mode averaging and shifting, eliminating the need for separate adjustment circuits and reducing overall complexity despite the enhanced functionality
Data Source
AI summary
A squelch detection device is provided. The squelch detection device receives first and second input signals and first and second threshold voltages. The squelch detection device determines a first common mode of the first and second input signals and a second common mode of the first and second threshold voltages. The squelch detection device averages the first common mode with the second common mode to produce an average common mode and sets the first common mode of the first and second input signals to the average common mode. The squelch detection device sets the second common mode of the first and second threshold voltages to the average common mode and determines a state of a squelch signal, indicative of whether the first and second input signals are attributable to noise, based on the first and second input signals and the first and second threshold voltages.