Guard Ring Snapback Layout for High-Voltage ESD Protection
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Solution Overview
Problem
Existing ESD protection devices for high side gate drivers in motorized machines are large in size, making them area inefficient and unable to effectively dissipate high ESD currents without causing voltage build-up and potential damage.
Innovation Solution
The development of a size-efficient ESD protection structure that integrates a bipolar transistor structure with a PN junction of high voltage devices, providing snapback protections and effectively discharging ESD current without significant area penalty.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional ESD protection devices are used, then ESD current can be dissipated, but the device size becomes large and area inefficient
Solution Approach 1:
The patent combines the ESD protection function with the existing guard ring structure around the high side gate driver. The guard ring is configured to receive ESD current and discharge it to ground, merging the protection function into the existing peripheral structure without requiring separate large ESD protection devices. This integration achieves effective ESD protection while maintaining compact die area.
2Reliability
If ESD protection devices are added, then high voltage build-up can be prevented, but the device complexity increases
Solution Approach 1:
The guard ring structure serves multiple functions: it provides electrical isolation for the high side gate driver and simultaneously acts as an ESD protection device. The same peripheral structure that defines the driver boundary also captures and discharges ESD current to ground, eliminating the need for additional dedicated ESD protection circuits and reducing overall device complexity.
3Reliability
If larger ESD protection devices are deployed, then ESD current dissipation improves, but area efficiency deteriorates
Solution Approach 1:
The patent utilizes the peripheral region around the high side gate driver in a different dimensional space. Instead of placing ESD protection devices within the driver area, the guard ring is positioned in the peripheral region, effectively using the boundary area to capture and discharge ESD current. This dimensional repositioning achieves effective ESD current dissipation without consuming additional die area.
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 ESD protection structure effectively protects high voltage circuit components from ESD events with high voltages (e.g., 1 kV or above) and high current density (e.g., 1 μA/μm) without increasing the die area, thus preventing damage and ensuring safe operation.
Implementation Method 1
During an electrostatic discharge (ESD) event, the high side gate driver may receive a large amount of current in a short period of time
Implementation Method 2
The bipolar transistor structure has a collector region near the PN junction, a base region embedded with sufficient pinch resistance to launch the snapback protection
Data Source
AI summary
An electrostatic discharge (ESD) protection structure that provides snapback protections to one or more high voltage circuit components. The ESD protection structure can be integrated along a peripheral region of a high voltage circuit, such as a high side gate driver of a driver circuit. The ESD protection structure includes a bipolar transistor structure interfacing with a PN junction of a high voltage device, which is configured to discharge the ESD current during an ESD event. The bipolar transistor structure has a collector region overlapping the PN junction, a base region embedded with sufficient pinch resistance to launch the snapback protection, and an emitter region for discharging the ESD current.