Current-Sensed Gate Driver Circuit for Lower Switching Loss
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Solution Overview
Problem
Existing gate driver circuits for voltage-driven power semiconductor switching devices face challenges in achieving high-speed switching operations during large-current driving, resulting in increased switching losses due to moderate di/dt and dv/dt profiles.
Innovation Solution
A gate driver circuit that includes a measurement unit to detect the current flowing in the power semiconductor switching device, allowing for variable mirror voltage and gate current control, thereby enhancing control accuracy and speeding up di/dt and dv/dt even during large-current driving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If large-current driving is performed with conventional gate driver circuits, then the device can handle high current loads, but di/dt and dv/dt become moderate resulting in increased switching losses
Solution Approach 1:
The gate driver circuit dynamically adjusts the gate resistance value based on the magnitude of the main circuit current. When large current is detected, the circuit automatically switches to a smaller gate resistance value, thereby increasing gate current and accelerating di/dt and dv/dt to reduce switching losses.
Solution Approach 2:
The invention changes the gate resistance parameter adaptively according to operating conditions. By switching between different resistance values (larger for small current, smaller for large current), the circuit optimizes the gate drive characteristics to achieve faster switching during high-current operation while maintaining controlled switching during low-current operation.
2Speed
If gate current is increased to speed up switching, then di/dt and dv/dt improve, but mirror voltage increases causing excessive power consumption
Solution Approach 1:
The gate driver employs dynamic resistance adjustment where the gate resistance value changes based on the main circuit current magnitude. During large-current operation, smaller resistance enables higher gate current and faster switching. During small-current operation, larger resistance limits gate current to reduce power consumption, thus dynamically optimizing the trade-off between switching speed and energy usage.
Solution Approach 2:
The circuit applies different gate drive characteristics (different resistance values) to match different operating conditions. By selecting appropriate resistance values locally adapted to the current magnitude, the system achieves optimal performance for each operating regime without excessive power consumption in low-current modes.
Data Source
AI summary
A gate driver circuit of a voltage drive type power semiconductor switching device capable of speeding up di/dt and dv/dt even during large-current driving to thereby reduce the switching loss is disclosed. This power semiconductor switching device gate driving circuit includes a drive circuit which applies a drive signal to the gate electrode of the power semiconductor switching device and a measurement unit for measuring a flow current of the power semiconductor switching device. Based on a detected value of the flow current of the power semiconductor switching device, the gate is made variable in mirror voltage thereof.