Shockley Diode ESD Protection for High-Speed Data Lines
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Solution Overview
Problem
Existing data transmission systems face limitations in electrostatic discharge (ESD) protection due to high clamping voltage and capacitance, which restrict data transmission rates and risk damage to voltage-sensitive components.
Innovation Solution
The implementation of a data transmission system utilizing a Shockley diode with a higher dopant concentration in specific doped subregions and a bypass trigger element, providing separate current paths for ESD current polarities and reducing line capacitance and clamping voltage through the use of forward-biased diodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a simple diode or thyristor is placed between the signal line and ground line for ESD protection, then the system provides basic ESD protection, but the clamping voltage is high and capacitance is high which limits data transmission rates
Solution Approach 1:
The ESD protection function is segmented into two separate paths: a first path with a Shockley diode for positive polarity ESD current and a second path with a diode for negative polarity ESD current. This segmentation allows each path to be optimized independently, achieving low clamping voltage and low capacitance while maintaining bidirectional ESD protection capability.
Solution Approach 2:
The patent applies different diode configurations to different polarity directions: the first path uses a Shockley diode with specific doping concentrations optimized for positive polarity protection, while the second path uses a standard diode for negative polarity protection. This local optimization allows each path to achieve minimal clamping voltage and capacitance for its specific function.
2Reliability
If a diode or thyristor is used for ESD protection, then the system provides voltage clamping, but the capacitance increases which restricts high-frequency data transmission
Solution Approach 1:
The patent changes the electrical parameters of the protection device by using a Shockley diode with specifically engineered doping concentrations. The inner p-doped region has a first doped subregion with higher dopant concentration than the second doped subregion, creating optimal electrical characteristics that minimize both clamping voltage and capacitance, thereby enabling high-frequency operation.
3Productivity
If a Shockley diode with higher dopant concentration in specific subregions is used, then the clamping voltage and capacitance are reduced, but the device structure becomes more complex
Solution Approach 1:
The Shockley diode structure implements local quality by creating a first doped subregion within the inner p-doped region that has higher dopant concentration than the surrounding second doped subregion. This localized doping variation optimizes the electrical characteristics for low capacitance and low clamping voltage without requiring complete structural redesign of the entire device.
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 solution achieves lower clamping voltage and capacitance, enabling faster data transmission rates while protecting components from ESD, by effectively steering ESD voltage away from the signal line and reducing power dissipation.
Implementation Method 1
When an ESD event occurs in a data transmission system, components of the data transmission system may be damaged if the discharge is not suitably dissipated by the system
Implementation Method 2
The first path Shockley diode may have a breakdown voltage that is greater than an expected data signal voltage level on the signal line
Implementation Method 3
providing separate current paths for ESD current polarities and reducing line capacitance and clamping voltage through the use of forward-biased diodes
Data Source
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AI summary
The disclosure relates to a data transmission system (100) comprising a signal line (101) and a ground line (103). A first signal path (102) is provided between the signal line (101) and the ground line (103). The first signal path (102) comprises a Shockley diode (104) having a cathode (106) and an anode (108). The cathode (106) is connected to the ground line (103) and the anode (108) is connected to the signal line (101).