Wide-Bandgap Switching Circuit RC Layout for Gate Ringing Suppression
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Solution Overview
Problem
Semiconductor circuits using wide bandgap semiconductors experience ringing due to parasitic inductance during high-speed switching, particularly at the gate, which can lead to erroneous switching and element breakdown.
Innovation Solution
A semiconductor circuit design that includes a switching circuit, a ground wiring, and a current detection circuit, with a noise eliminating RC series circuit connected in parallel between the switching circuit and the ground wiring, and optionally incorporating a half or full bridge circuit configuration with transistors or diodes, and the current detection and noise eliminating circuits can be partially or fully accommodated within a package.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-speed switching is performed using wide bandgap semiconductor, then power and frequency are improved, but ringing is generated due to parasitic inductance
Solution Approach 1:
A noise eliminating circuit is introduced as an intermediary component between the switching element and ground wiring. This circuit acts as a mediator to suppress ringing by providing an alternative current path that bypasses the parasitic inductance, thereby eliminating the harmful oscillations while preserving the high-power capability of wide bandgap semiconductors
2Measurement precision
If current detection circuit is connected with large impedance, then current detection precision is improved, but ringing is generated in gate via capacitance
Solution Approach 1:
The noise eliminating circuit serves as an intermediary that decouples the current detection circuit from the ringing source. By providing a parallel current path with lower impedance to ground, it prevents ringing from coupling through the capacitance to the gate, allowing the current detection circuit to maintain high impedance for precise measurement without causing gate ringing
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
The design effectively suppresses ringing at the gate of the switching element, optimizing the noise eliminating circuit's characteristics and reducing impedance, thereby preventing erroneous switching and element breakdown.
Implementation Method 1
a noise eliminating circuit is connected between the switching circuit and the ground wiring in a parallel relationship with respect to the current detection circuit
Implementation Method 2
the noise eliminating circuit is an RC series circuit where a resistor and a capacitor are connected in series
Data Source
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AI summary
[Problem] To provide a semiconductor circuit that uses a semiconductor circuit including a wideband gap semiconductor, and can suppress ringing that occurs in a gate of a switching element. [Means] A semiconductor circuit 1 includes: a switching circuit 10 having at least one switching element Q; a ground wiring 50; and a current detection circuit 30 connected between the switching circuit 10 and the ground wiring 50. A noise eliminating circuit 40 is connected between the switching circuit 10 and the ground wiring 50 in a parallel relationship with respect to the current detection circuit 30.