USB-C BMC Threshold Adjustment for Out-of-Spec Cable Signals
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Solution Overview
Problem
USB cables often fail to meet specification requirements due to production errors or degradation, leading to variations in impedance that affect BMC signal communication, making it challenging to maintain effective power delivery through USB-C connections.
Innovation Solution
A threshold adjustment circuit and comparator system within USB elements, such as hosts or devices, dynamically adjust the BMC signal threshold based on input signal durations to ensure balanced logic high and low times, correcting for impedance changes and ensuring proper power negotiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a switch and capacitor are applied to correct BMC signals, then signal accuracy is improved, but device size and cost increase due to large capacitor requirements
Solution Approach 1:
The patent changes the operating parameters by using dynamic threshold adjustment instead of passive capacitor filtering. The threshold is dynamically modified based on detected signal characteristics to accommodate cable impedance variations, achieving signal correction without requiring large capacitors.
Solution Approach 2:
The patent replaces the mechanical/electrical filtering approach (switch and capacitor) with an electronic signal processing approach (comparator with dynamic threshold adjustment). This substitution eliminates the need for large physical capacitors while maintaining signal correction functionality.
2Measurement precision
If a switch and capacitor are applied to correct BMC signals, then signal accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The patent changes the operating parameters by using dynamic threshold adjustment instead of passive capacitor filtering. The threshold is dynamically modified based on detected signal characteristics to accommodate cable impedance variations, achieving signal correction without requiring large capacitors.
Solution Approach 2:
The patent replaces the mechanical/electrical filtering approach (switch and capacitor) with an electronic signal processing approach (comparator with dynamic threshold adjustment). This substitution eliminates the need for large physical capacitors while maintaining signal correction functionality.
3Stability of the object's composition
If large capacitors are used for BMC signal correction, then signal stability is improved, but integration into semiconductor dies becomes prohibitively expensive
Solution Approach 1:
The patent changes the operating parameters by using dynamic threshold adjustment instead of passive capacitor filtering. The threshold is dynamically modified based on detected signal characteristics to accommodate cable impedance variations, achieving signal correction without requiring large capacitors.
Solution Approach 2:
The patent replaces the mechanical/electrical filtering approach (switch and capacitor) with an electronic signal processing approach (comparator with dynamic threshold adjustment). This substitution eliminates the need for large physical capacitors while maintaining signal correction functionality.
Data Source
AI summary
An apparatus includes a bi-phase mark coded (BMC) input port configured to receive BMC signals from a universal serial bus (USB) cable. The apparatus further includes a threshold adjustment circuit configured to generate a threshold, and a comparator configured to compare an input BMC signal from the BMC input port and the threshold and based on the comparison, generate an adjusted input BMC signal. The threshold adjustment circuit is further configured to adjust the threshold based upon the input BMC signal.