Semiconductor Gate Drive Circuit With Feedback-Timed Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor device drive circuits for power switching devices, such as IGBTs, face challenges in minimizing switching losses due to misalignment of switching timing, leading to increased unnecessary operation and energy inefficiency.
Innovation Solution
A semiconductor device drive circuit comprising a first and second transistor connected in series, an internal power supply circuit with a constant voltage generation unit and feedback unit, and a pre-driver that adjusts the internal power supply voltage based on the node voltage between the transistors, allowing for controlled output current changes during switching to improve switching efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the output voltage of the pre-driver is transitioned between L and H at any timing in response to the output current, then the output current of the output transistor changes, but switching losses increase due to misalignment of switching timing
Solution Approach 1:
The patent applies feedback control by monitoring the output current of the output transistor and using this information to control the pre-driver output voltage timing. The control unit transitions the pre-driver output between L and H at timings determined by the output current state, creating a closed-loop system that aligns switching events with the actual current state to prevent unnecessary switching losses while maintaining fast switching response
Solution Approach 2:
The patent implements preliminary action by transitioning the pre-driver output voltage before the actual switching event occurs. The control unit anticipates the need for switching by changing the pre-driver output in advance, allowing the output transistor to switch more efficiently without causing unnecessary losses, thus preparing the system proactively for the upcoming switching requirement
Data Source
AI summary
A semiconductor device drive circuit includes: a first transistor and a second transistor operating complementarily between a first voltage and a second voltage lower than the first voltage; an internal power supply circuit operating between the first voltage and the second voltage, and including: a constant voltage generation unit outputting an internal power supply voltage steadily being a constant voltage; and a feedback unit receiving a node voltage of a connection node between the first transistor and the second transistor, and changing the internal power supply voltage output from the constant voltage generation unit in response to a change of the node voltage; and a pre-driver operating between the first voltage and the internal power supply voltage, and driving the first transistor or the second transistor, wherein the node voltage is output as a gate voltage of the power switching device.