GaN Substrate Clamping Circuit for Bidirectional Switch dV/dt Events
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor-based circuits experience unpredictable performance due to voltage changes on the substrate, leading to undesirable voltage excursions, particularly during high-rate voltage transitions (dV/dt events), which affect the reliability and predictability of bidirectional switches.
Innovation Solution
A clamping circuit is implemented on a GaN substrate with a mirrored diode circuit to clamp positive dV/dt events and a mirrored switch circuit to clamp negative dV/dt events, using transistors and diodes to maintain substrate voltage within a threshold, thereby reducing voltage variations and ensuring predictable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a bidirectional transistor switch is used on a semiconductor substrate, then the switching performance is improved, but voltage excursions on the substrate occur during high-rate voltage transitions (dV/dt events)
Solution Approach 1:
A clamping circuit is introduced as an intermediary component between the bidirectional transistor switch and the substrate. This circuit includes diodes connected to the substrate that activate during dV/dt events to clamp voltage excursions, allowing the switch to operate at high performance while the clamping circuit maintains substrate voltage stability
2Device complexity
If the substrate voltage is allowed to change freely, then the circuit operation is simpler, but the electrical performance becomes unpredictable
Solution Approach 1:
The clamping circuit is designed to automatically activate during dV/dt events without external control. The diodes in the clamping circuit self-regulate the substrate voltage by conducting current when voltage excursions occur, providing self-service voltage stabilization that maintains predictable performance without adding complex control mechanisms
Data Source
AI summary
An electronic device includes a semiconductor substrate and a bidirectional transistor switch formed on the substrate, the bidirectional switch including a first source node, a second source node and a common drain node. A first transistor is formed on the substrate and includes a first source terminal, a first drain terminal and a first gate terminal, wherein the first source terminal is connected to the substrate, the first drain terminal is connected to the first source node and the first gate terminal is connected to the second source node. A second transistor is formed on the substrate and includes a second source terminal, a second drain terminal and a second gate terminal, wherein the second source terminal is connected to the substrate, the second drain terminal is connected to the second source node and the second gate terminal is connected to the first source node.