GaN Substrate Clamping Circuit for Bidirectional Switch dV/dt Control
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 switch operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If bidirectional switches are used on semiconductor substrate, then switching capability is improved, but voltage excursions during dV/dt events cause unpredictable performance
Solution Approach 1:
A clamping circuit is introduced as an intermediary component between the bidirectional switch and the substrate. This circuit includes diodes connected to substrate nodes that actively clamp voltage excursions during dV/dt events, preventing unpredictable performance while preserving the bidirectional switching capability of the main circuit
2Device complexity
If substrate voltage is left uncontrolled, then circuit simplicity is maintained, but voltage excursions during dV/dt events occur causing performance degradation
Solution Approach 1:
The clamping circuit is designed to act preemptively during dV/dt events by incorporating diodes that automatically activate when voltage excursions occur. The diodes are positioned and biased to clamp substrate node voltages before they can cause performance degradation, providing preliminary protection without requiring complex control logic
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.