Multi-Threshold Decoding Circuit for USB PD Noise Drift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Noise interference during USB PD protocol data delivery affects the effectiveness of data reception, particularly due to DC voltage level drifts, leading to decoding errors.
Innovation Solution
A decoding method and circuit that utilize multiple comparators and a noise filtering and signal edge detection circuit to adjust edge detection strategies, comparing voltage levels with reference voltages to generate and select an optimum edge detection signal for accurate decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional single threshold edge detection is used, then the decoding process is simple, but noise interference causes decoding errors
Solution Approach 1:
The patent divides the single threshold edge detection into three separate edge detection circuits with different thresholds (first threshold < second threshold < third threshold). Each circuit independently detects edges, and the results are combined through logical operations to produce the final decoded signal. This segmentation allows the system to handle noise interference more effectively by comparing multiple detection results.
Solution Approach 2:
The patent applies different threshold values to different edge detection circuits based on their specific functions. The first edge detection circuit uses a lower threshold to detect rising edges, while the third uses a higher threshold to detect falling edges. This local differentiation of threshold quality enables each circuit to optimize its detection for specific signal conditions.
2Reliability
If multiple edge detection circuits are used to reduce noise influence, then decoding accuracy improves, but the circuit complexity increases
Solution Approach 1:
The patent merges three separate edge detection circuits into a unified decoder structure where their outputs are combined through logical operations. The first and third edge detection signals are combined to generate the final decoded signal, effectively merging multiple detection results into a single reliable output that resists noise interference.
Solution Approach 2:
The decoder circuit is designed to perform multiple functions: it detects rising edges, detects falling edges, filters noise, and generates the final decoded signal. By making the decoder multi-functional, the patent reduces the need for separate dedicated circuits for each function, thereby managing complexity while maintaining reliability.
3Object-affected harmful factors
If DC voltage level drift compensation is implemented, then noise resistance improves, but the decoding process becomes more complex
Solution Approach 1:
The patent changes the threshold parameters of the edge detection circuits to compensate for DC voltage level drift. By adjusting the threshold values (first threshold, second threshold, third threshold) based on expected drift conditions, the system maintains accurate edge detection despite voltage variations, effectively compensating for noise without adding complex active compensation circuits.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures correct decoding of digital signals by reducing the influence of noise on power signal lines, minimizing decoding errors caused by noise interference.
Implementation Method 1
comparing a voltage level of an analog signal to be decoded with multiple reference voltages to generate a current level number
Implementation Method 2
performing an edge detection process using the current level number at each time to obtain a first edge detection signal
Data Source
AI summary
The preferred embodiment of the present disclosure relates to a decoding method for reducing the influence of noise power signal line and a decoding circuit. The method includes: dividing an analog signal to be decoded into a plurality of levels; performing an edge detection according to the levels to obtain a first edge detection signal; setting the levels which is smaller than a lower level to the lower level and performing the edge detection to obtain the second edge detection signal; setting the levels which is greater than a higher level to the higher level and performing the edge detection to obtain a third edge detection signal; decoding the first, the second, the third edge detection signal to obtain an optimum edge detection signal.