Silicon-Controlled Rectifier ESD Protection with Isolated Ground Lines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional silicon-controlled rectifier (SCR) ESD protection circuits for integrated circuits suffer from instability in the main ground voltage line due to noise interference from the peripheral ground voltage line, which can compromise the stability of the main ground voltage.
Innovation Solution
An ESD protection circuit with silicon-controlled rectifier characteristics that includes an anode connected to a signal line, a first cathode connected to a main ground line, a second cathode connected to a peripheral ground line, a PNP transistor, an NPN transistor, and an isolation device to electrically isolate the first cathode from the second cathode, maintaining the stability of the main ground voltage line by preventing noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the main ground voltage line and peripheral ground voltage line are connected to the same P+ region, then the ESD protection circuit can be simplified in structure, but the main ground voltage becomes unstable due to noise interference from the peripheral ground voltage line
Solution Approach 1:
The patent divides the ground voltage system into two separate P+ regions: one dedicated to the main ground voltage line and another for the peripheral ground voltage line. This segmentation physically isolates the two ground lines, preventing noise from the peripheral ground from affecting the main ground voltage stability while maintaining ESD protection functionality.
2Reliability
If the main ground voltage line is isolated from the peripheral ground voltage line, then the main ground voltage stability is improved, but the ESD protection circuit complexity increases
Solution Approach 1:
The patent combines the ESD protection function with the ground voltage isolation function into a unified structure. The SCR circuit (comprising PNP and NPN transistors) serves both to provide ESD protection and to electrically isolate the main and peripheral ground lines through its inherent transistor configuration, thereby achieving dual functionality without proportionally increasing circuit complexity.
Data Source
AI summary
A Silicon-Controlled Rectifier (SCR) for Electrostatic Discharge (ESD) protection includes an isolation device. The isolation device isolates a main ground voltage line, connected to a first cathode, from a peripheral ground voltage line, connected to a second cathode. As result, even when noise occurs in the peripheral ground voltage line during the operation of an integrated circuit, the main ground voltage line maintains a stable voltage level.