Integrated Switch Module Short-Circuit Detection Without External Components
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Solution Overview
Problem
Conventional short circuit detection methods for power transistors, such as desaturation detection, can be too slow and require additional components, which may limit performance and increase parasitic effects.
Innovation Solution
A switch module with an integrated short circuit detection circuit that detects short circuits between load terminals and electrically couples the control terminal to the first load terminal, utilizing power from the voltage between the control terminal and the first load terminal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional desaturation detection is used for short circuit monitoring, then the power transistor can be protected from short circuits, but the detection speed is too slow and additional components are required
Solution Approach 1:
The short circuit detection circuit is merged with the transistor switch package, integrating the detection functionality directly into the power transistor structure. This eliminates the need for separate external detection components and enables faster response by reducing signal path length and component interaction delays.
Solution Approach 2:
The patent introduces an intermediary detection mechanism that monitors the voltage between the control terminal and the first load terminal. This intermediary signal provides early warning of short circuit conditions before they develop into full desaturation events, enabling faster protection response.
2Reliability
If conventional desaturation detection is used for short circuit monitoring, then the power transistor can be protected from short circuits, but additional components outside the transistor package are required
Solution Approach 1:
The detection circuit is combined with the transistor switch within a single package, eliminating the need for separate external diodes and detection components. This integration reduces the total component count and simplifies the overall circuit design while maintaining reliable short circuit protection.
Solution Approach 2:
The integrated detection circuit utilizes existing transistor terminals and internal structures to perform both switching and detection functions. By making the detection circuit multi-functional with the transistor structure itself, additional external components are eliminated.
3Reliability
If additional components like diodes are added for short circuit detection, then the power transistor can be protected, but parasitic effects increase and performance is limited
Solution Approach 1:
By merging the detection functionality with the transistor structure itself, the patent eliminates external diodes and associated parasitic elements. The detection circuit uses the transistor's own terminals and internal characteristics, removing the harmful parasitic effects introduced by external components.
Solution Approach 2:
The patent extracts the detection functionality from external components and relocates it within the transistor package. This extraction removes the parasitic effects associated with external diodes and interconnection traces, leaving only the essential protection function.
Data Source
AI summary
Switch modules, driver circuits for switch modules and corresponding methods are provided. In an implementation, a switch module includes a transistor switch and a short circuit detection circuit. The transistor switch includes a control terminal, a first load terminal and a second load terminal. The short circuit detection circuit is configured to detect a short circuit state between the first load terminal and the second load terminal and to automatically switch off the transistor switch without additional signaling, by automatically electrically coupling the control terminal to the first load terminal in response to detecting the short circuit state. The short circuit detection circuit is energized by a voltage between the control terminal and the first load terminal.