Semiconductor ESD Protection for Multi-Power Supply Systems
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Solution Overview
Problem
Semiconductor devices with different power supply systems face challenges in protecting output transistors from electrostatic breakdown, as existing ESD protection circuits, such as GGNMOS transistors and diode elements, are ineffective when static electricity is applied across power supply system boundaries, leading to increased resistance and potential transistor breakdown.
Innovation Solution
A semiconductor device configuration that includes a first and second power supply system, an output circuit, a driving circuit, and protection elements connected between the output node and ground voltages, forming direct discharge paths to prevent electrostatic breakdown, with additional protection elements between ground voltages to ensure efficient discharge even with long interconnects or high resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a GGNMOS transistor is used as an ESD protection circuit, then electrostatic protection is effective for circuits receiving power from the same power supply system, but the protection becomes ineffective when static electricity is applied through nodes interconnecting circuits at the boundary between different power supply systems
Solution Approach 1:
The ESD protection function is segmented into multiple dedicated protection elements: one for the first power supply system (first protection element between first output node and first ground), another for the second power supply system (second protection element between second output node and second ground), and a third protection element specifically for the boundary node (third protection element between boundary node and first ground). Each segment handles protection for its specific power supply domain independently.
Solution Approach 2:
The third protection element acts as an intermediary specifically for the boundary node where different power supply systems interconnect. This intermediary element provides a dedicated discharge path for static electricity at the critical interface between power supply systems, where conventional protection elements fail to provide adequate protection.
2Adaptability or versatility
If the output pad is formed at a location separated from the diode element, then design flexibility is improved, but the resistance value on the discharge path increases causing the output transistor to be broken down by static electricity
Solution Approach 1:
The protection architecture is segmented into multiple independent protection elements placed at different locations throughout the circuit. This segmentation allows the output pad to be placed flexibly at various positions while maintaining adequate protection, as each segment provides local protection without requiring close proximity to a single centralized protection element.
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
The proposed configuration effectively protects output transistors from electrostatic breakdown by forming direct discharge paths and reducing the influence of resistance, ensuring reliable operation across different power supply systems.
Implementation Method 1
One end of the first protection element is connected to an output node of the output circuit and the other end is connected to the first ground voltage... forming direct discharge paths to prevent electrostatic breakdown
Data Source
AI summary
A semiconductor device comprises a first power supply system, a second power supply system, an output circuit, a first driving circuit and a first protection. The first power supply system is configured with a first power supply voltage and a first ground voltage. The second power supply system is configured with a second power supply voltage and a second ground voltage. The output circuit receives a power supply from the second power supply system. The first driving circuit receives a power supply from the first power supply system and outputs a signal for driving the output circuit. One end of the first protection element is connected to an output node of the output circuit and the other end is connected to the first ground voltage.