Power Semiconductor Gate Return Circuit for Multi-Level di/dt Control
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Solution Overview
Problem
Existing power semiconductor devices face challenges in achieving optimal switching performance due to the need to compromise between low and high switching currents, and closed-loop gate drive control methods require high design bandwidth, leading to stability and complexity issues.
Innovation Solution
A power semiconductor device with multiple inductance/resistance pairs and a control circuit that forms a gate drive current return loop through these pairs, allowing for multi-level di/dt control and reducing switching losses and turn-on/off time delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If fixed-value gate resistors are used to reduce reverse recovery current and diode transition power loss, then switching losses are reduced, but switching performance must be compromised between low and high switching currents
Solution Approach 1:
The patent applies dynamics by replacing fixed-value gate resistors with a dynamic resistance selection mechanism. The control circuit can dynamically select between multiple gate resistors with different resistance values based on operating conditions, enabling optimal switching performance across varying current levels while minimizing switching losses.
Solution Approach 2:
The patent implements parameter changes by providing multiple gate resistors with different resistance values and selecting the appropriate resistor based on the switching current level. This allows the gate drive circuit to adapt its resistance parameter to match operating conditions, optimizing both low and high current switching performance without energy loss compromise.
2Manufacturing precision
If closed-loop gate drive control method is used to achieve good control of switching transient, then switching transient control is improved, but design bandwidth requirement increases resulting in stability and complexity challenges
Solution Approach 1:
The patent applies segmentation by dividing the gate drive control into discrete resistance value selections rather than continuous closed-loop control. The control circuit segments the switching transient control into manageable stages by selecting from predefined resistance values, reducing the bandwidth requirement and simplifying the control architecture while maintaining effective transient control.
Solution Approach 2:
The patent uses simple, discrete gate resistors instead of complex closed-loop control components. By selecting from multiple fixed-value resistors rather than implementing sophisticated active control circuitry, the solution achieves effective switching transient control with simpler, more reliable, and easier to manufacture components.
3Loss of energy
If power semiconductor device switches as fast as possible to achieve minimum turn-on and turn-off power losses, then power losses are minimized, but freewheeling diode requires slow transition to reduce reverse recovery current
Solution Approach 1:
The patent applies dynamics by enabling the gate drive circuit to dynamically adjust its resistance based on the switching phase and current conditions. During turn-on, the circuit can select lower resistance values for faster switching and minimum power loss, while during turn-off with freewheeling diode operation, it can select higher resistance values to slow the transition and reduce reverse recovery current.
Solution Approach 2:
The patent implements parameter changes by providing multiple gate resistors with different resistance values that can be selected based on the operating mode. This allows the system to change the gate drive resistance parameter to optimize for either fast switching (minimum power loss) or slow transition (reduced reverse recovery current) as needed.
Data Source
AI summary
A power semiconductor device has a power semiconductor die forming a power switch with an input pad, an output pad, and a control pad; a collector power terminal coupled to the input pad of the power switch; an auxiliary gate terminal coupled to the control pad of the power switch; an emitter power terminal; two or more inductance/resistance pairs, with each inductance/resistance pair having a common stray inductance and a resistance arranged in series between the output pad of the power switch and the emitter power terminal; and a plurality of auxiliary emitter terminals that are coupled to both sides of the inductance/resistance pairs so that one auxiliary emitter terminal is coupled to one side of one inductance/resistance pair. A control circuit for di/dt control can control the power semiconductor device. An electronic device can include the power semiconductor device and control circuit.