Gate Driver Circuit With Programmable Gate Capacitance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gate driver technologies for semiconductor power switching devices, such as MOSFETs and IGBTs, lack flexibility in adjusting switching characteristics, with switching speed being non-programmable and requiring changes to gate resistors for speed modifications.
Innovation Solution
A gate driver circuit with a controllable capacitor circuit that provides adjustable external gate capacitance in parallel with the internal capacitance, allowing selective control of external gate capacitance values through controllable capacitor legs, enabling flexible adjustment of switching characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a gate resistor is used to control switching speed, then the switching characteristics can be adjusted, but the switching speed becomes non-programmable and requires physical component changes for adjustment
Solution Approach 1:
The patent changes the parameter being controlled from resistance (fixed physical component) to capacitance (programmable through switching capacitor elements). By using a capacitor circuit with switchable capacitance values, the gate driver can be programmed to provide different external gate capacitances, enabling flexible and programmable adjustment of switching characteristics without requiring physical component changes.
2Ease of operation
If the gate resistor value is changed to modify switching speed, then switching characteristics are adjusted, but this requires physical component replacement rather than electronic programming
Solution Approach 1:
The patent transforms the static gate resistor into a dynamic capacitor circuit with switchable capacitance values. The capacitor circuit can be electronically controlled to provide different capacitance values during operation, enabling dynamic and programmable adjustment of switching characteristics without requiring physical component replacement.
3Device complexity
If a fixed gate capacitance is used, then the circuit is simple, but the switching characteristics cannot be flexibly adjusted or programmed
Solution Approach 1:
The patent segments the gate capacitance into multiple discrete capacitor elements that can be independently switched. This segmentation allows the circuit to provide different total capacitance values by connecting or disconnecting individual capacitor elements, achieving programmable switching characteristics while maintaining relatively simple circuit architecture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables programmable control of switching speed, delay, and current change rates, reducing magnetic interference and common-mode currents, and optimizing switching synchronicity across parallel-connected devices.
Implementation Method 1
a controllable capacitor circuit configured to provide an adjustable external gate capacitance at the gate driver output in parallel with an internal gate capacitance of the semiconductor power switching device
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
A gate driver (14) includes a switching circuit outputting a gate driving voltage (Vge) to a gate (G) of a semiconductor power switching device (IGBT) via a series gate resistor (Rg). The gate driver further includes an external controllable capacitor circuit (20) is coupled at the gate of the semiconductor power switching device (IGBT) to provide an adjustable external gate capacitance (CG) in parallel with a parasitic gate or input capacitance (Cge) of the IGBT. The capacitor circuit (20) may be controlled by one or more electrical signals (Con_CG) to vary the external gate capacitance (CG) and thereby the characteristics of a switching operation.