Adaptive Semiconductor Switch Driving Circuit for Loss Reduction
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Solution Overview
Problem
Existing semiconductor switch driving circuits face a trade-off between minimizing switching losses and managing voltage stress, with smaller resistance leading to faster switching speed but increased voltage stress, and larger resistance resulting in higher switching losses.
Innovation Solution
A driving circuit with multiple turn-off driving units having different parameters is used, allowing for adaptive selection based on the semiconductor switch's working state to optimize switching speed and reduce losses while maintaining voltage stress within safe limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the resistance of the driving resistor is decreased to increase switching speed, then switching losses are reduced, but voltage stress on the semiconductor switch increases
Solution Approach 1:
The patent applies dynamics by making the turn-off resistance variable rather than fixed. The driving circuit dynamically adjusts the turn-off resistance based on the working current magnitude: using a first turn-off resistance for normal current conditions and a second turn-off resistance for overload current conditions. This dynamic adjustment optimizes switching speed while preventing excessive voltage stress under different operating conditions.
Solution Approach 2:
The patent changes the resistance parameter adaptively based on working conditions. By detecting the magnitude of working current and selecting different resistance values (first turn-off resistance vs. second turn-off resistance), the system optimizes the balance between switching speed and voltage stress for each specific operating state.
2Loss of energy
If a fixed turn-off resistance is used, then the circuit is simple, but switching losses cannot be optimized under varying current conditions
Solution Approach 1:
The patent segments the turn-off resistance function into multiple resistance values (first turn-off resistance and second turn-off resistance) that are selectively applied based on current conditions. This segmentation allows optimization of switching losses for different operating ranges while maintaining manageable circuit complexity through structured design.
Solution Approach 2:
The patent implements feedback by detecting the magnitude of working current and using this information to select the appropriate turn-off resistance. The detection unit monitors current conditions and provides feedback to the driving circuit, which then adjusts the resistance selection to minimize switching losses under varying load conditions.
Data Source
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AI summary
The present application discloses a driving circuit for a semiconductor switch. The driving circuit includes a driving unit, a sampling unit (201) and a selection unit (202). A plurality of turn-off driving units with different turn-off parameters is provided in the driving unit, and a turn-off driving unit having a turn-off parameter adaptive to the working state of the semiconductor switch is selected according to the working state of the semiconductor switch so as to turn off the semiconductor switch.