Transmission Circuit Ground Line Shielding for Crosstalk Reduction
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Solution Overview
Problem
High-speed differential signals used in semiconductor device communication are prone to noise interference, particularly crosstalk, which degrades signal quality due to their higher speed and lower amplitude compared to single-ended signals.
Innovation Solution
A transmission circuit configuration is implemented with a specific arrangement of signal lines and a ground line, where the distance between the differential signal lines and the ground line is greater than between the differential signal lines themselves, reducing electromagnetic coupling and crosstalk noise by creating a shield effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If differential signals are transmitted at high speed with lower amplitude, then data transmission capacity is improved, but signal quality deteriorates due to increased susceptibility to crosstalk noise
Solution Approach 1:
A ground line is introduced as an intermediary element between the first signal line and the third signal line. This ground line acts as a shield that intercepts and redirects electromagnetic fields, preventing crosstalk noise from affecting the differential signals while allowing high-speed data transmission to continue
2Area of stationary object
If signal lines are arranged closely together, then wiring board area is reduced, but crosstalk noise increases affecting differential signal quality
Solution Approach 1:
The ground line serves as a physical intermediary barrier positioned between adjacent signal lines. Even when signal lines are arranged closely to minimize wiring board area, the ground line intercepts electromagnetic coupling between them, preventing crosstalk noise while maintaining the compact layout
Solution Approach 2:
The ground line is strategically positioned only between specific signal lines where crosstalk is most problematic. This localized shielding approach reduces crosstalk noise in critical areas without requiring uniform spacing between all signal lines, thus optimizing the use of wiring board area
3Length of moving object
If the distance between signal lines and ground line is reduced, then wiring structure becomes thinner, but electromagnetic coupling increases causing more crosstalk noise
Solution Approach 1:
The patent optimizes the distance parameter between the first signal line and the ground line. By carefully controlling this distance to be within a specific range, the wiring structure thickness is reduced while the ground line continues to effectively shield against crosstalk noise through its proximity to the signal lines
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
This configuration effectively maintains high-quality differential signals by minimizing crosstalk noise, even at high speeds, and allows for a thinner, more flexible wiring structure in electronic devices.
Implementation Method 1
A distance between the first signal line and the ground line is larger than a distance between the first signal line and the second signal line
Data Source
AI summary
A transmission circuit includes a first semiconductor device, a second semiconductor device, a first signal line, a second signal line, a third signal line, and a ground line. A differential signal is composed of a first signal and a second signal. The first signal line is configured to connect the first semiconductor device and the second semiconductor device and used to transmit the first signal. The second signal line is configured to connect the first semiconductor device and the second semiconductor device and used to transmit the second signal. The second signal line, the first signal line, the ground line, and the third signal line are disposed in this order. A distance between the first signal line and the ground line is larger than a distance between the first signal line and the second signal line.