Power Module Terminal Segmentation for EMI Noise Reduction
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Solution Overview
Problem
High-power SIC and GaN power modules experience significant EMI noise due to high parasitic parameters and high-speed switching characteristics, which complicates electromagnetic compatibility and requires innovative solutions to reduce noise effectively.
Innovation Solution
The power module incorporates at least one non-jumping and one jumping power terminal, with high-frequency capacitors connected between the non-jumping terminals and power inductors to minimize EMI noise, reducing the impedance and noise amplitude across terminals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high-speed switching devices (SIC/GaN) are used to achieve high power density and fast switching, then switching speed and power density are improved, but EMI noise increases due to high dv/dt and di/dt
Solution Approach 1:
The power module terminals are segmented into jumping terminals (connected to switching nodes with high dv/dt) and non-jumping terminals (connected to stable potential nodes). This segmentation isolates the EMI noise source at jumping terminals from sensitive circuits connected to non-jumping terminals, allowing high-speed switching to be maintained while protecting against EMI noise propagation.
Solution Approach 2:
High-frequency capacitors are introduced as intermediary elements connected between non-jumping terminals. These capacitors act as EMI filters that shunt high-frequency noise to ground while maintaining the stable potential reference, thereby reducing EMI noise without affecting the high-speed switching performance of the power devices.
2Loss of energy
If parasitic parameters are reduced in power modules to improve switching performance, then switching loss is reduced, but EMI noise becomes more prominent due to higher dv/dt and di/dt
Solution Approach 1:
The terminal structure is segmented into jumping and non-jumping types, creating distinct electrical zones. Jumping terminals accommodate high dv/dt nodes while non-jumping terminals provide stable references. This segmentation allows minimal parasitic inductance in switching paths (reducing switching loss) while isolating EMI noise from sensitive circuits.
Solution Approach 2:
High-frequency capacitors serve as intermediary elements that decouple the low-parasitic switching nodes from sensitive load circuits. These capacitors filter the high-frequency EMI noise generated by low-parasitic fast switching, allowing the benefits of reduced switching loss to be realized without the penalty of excessive EMI noise.
3Ease of manufacture
If standard discrete component packaging is used to maintain low cost and high reliability, then manufacturing cost and reliability are improved, but parasitic parameters increase leading to EMI problems
Solution Approach 1:
The power module adopts a segmented terminal architecture where jumping and non-jumping terminals are clearly defined and separately handled in the PCB layout. This segmentation allows standard discrete component packaging to be used (maintaining manufacturing simplicity) while the terminal classification enables effective EMI management through proper grounding and filtering strategies.
Solution Approach 2:
High-frequency capacitors are added as intermediary filtering elements in the power module. These capacitors compensate for the increased parasitic parameters inherent in standard discrete packaging by providing low-impedance EMI filtering paths, thereby reducing EMI noise without requiring exotic low-parasitic components or complex packaging.
4Object-generated harmful factors
If EMI filtering components are added to reduce noise, then EMI noise is reduced, but device complexity and engineering time increase
Solution Approach 1:
The terminal segmentation into jumping and non-jumping types provides a systematic framework for EMI management. This segmentation simplifies the design process by providing clear guidelines for PCB layout, grounding, and capacitor placement, thereby reducing the complexity that would otherwise arise from trial-and-error EMI filtering design.
Solution Approach 2:
High-frequency capacitors are strategically placed as intermediary elements at specific non-jumping terminals. This targeted approach to filtering, guided by the terminal segmentation theory, reduces EMI noise effectively while minimizing the number of components required, thereby avoiding excessive device complexity.
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
This configuration significantly reduces EMI noise, meeting Class B standards for electromagnetic compatibility and saving engineering time in noise mitigation, while being applicable to various power module topologies like boost, buck, and half-bridge circuits.
Implementation Method 1
至少一个第二电容器 electrically connected between the third non-jumping power terminal and at least one of the other non-jumping power terminals
Data Source
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AI summary
The present disclosure provides power module (M), comprising at least three non-jumping power terminals (IN+, IN-, OUT) at a non-jumping potential, wherein multiple power devices (Qi, Q2) and at least one first capacitor (C1) are electrically connected between a first non-jumping power terminal (IN+) and a second non-jumping power terminal (IN-) of the at least three non-jumping power terminals; and at least one jumping power terminal at a jumping potential. A first jumping power terminal (AC) of the at least one jumping power terminal is electrically connected to one terminal of a power inductor and a third non-jumping power terminal (OUT) of the at least three non-jumping power terminals (IN+, IN-, OUT) is electrically connected to the other terminal of the power inductor; wherein at least one second capacitor (C2) is electrically connected between the third non-jumping power terminal (OUT) and at least one of other non-jumping power terminals (IN+, IN-).