scholarly journals An RF Approach to Modelling Gallium Nitride Power Devices Using Parasitic Extraction

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2007
Author(s):  
Nikita Hari ◽  
Sridhar Ramasamy ◽  
Mominul Ahsan ◽  
Julfikar Haider ◽  
Eduardo M. G. Rodrigues
Keyword(s):  
High Speed ◽  
Power Devices ◽  
Parasitic Extraction ◽  
Switching Model ◽  
Pulse Test ◽  
Gan Hemt ◽  
Proposed Model ◽  
Original Contribution ◽  
Network Analyser ◽  
High Speed Switching

This paper begins with a comprehensive review into the existing GaN device models. Secondly, it identifies the need for a more accurate GaN switching model. A simple practical process based on radio frequency techniques using Vector Network Analyser is introduced in this paper as an original contribution. It was applied to extract the impedances of the GaN device to develop an efficient behavioural model. The switching behaviour of the model was validated using both simulation and real time double pulse test experiments at 500 V, 15 A conditions. The proposed model is much easier for power designers to handle, without the need for knowledge about the physics or geometry of the device. The proposed model for Transphorm GaN HEMT was found to be 95.2% more accurate when compared to the existing LT-Spice manufacturer model. This work additionally highlights the need to adopt established RF techniques into power electronics to reduce the learning curve while dealing with these novel high-speed switching devices.

4H-SIC Dmosfets for High Frequency Power Switching Applications

2003 ◽  
Vol 764 ◽  
Author(s):  
Sei-Hyung Ryu ◽  
Anant K. Agarwal ◽  
James Richmond ◽  
John W. Palmour
Keyword(s):  
High Voltage ◽  
High Speed ◽  
High Performance ◽  
High Frequency Power ◽  
Power Devices ◽  
Power Switching ◽  
High Speed Switching ◽  
Unipolar Devices ◽  
Very High ◽  
Frequency Power

AbstractVery high critical field, reasonable bulk electron mobility, and high thermal conductivity make 4H-Silicon carbide very attractive for high voltage power devices. These advantages make high performance unipolar switching devices with blocking voltages greater than 1 kV possible in 4H-SiC. Several exploratory devices, such as vertical MOSFETs and JFETs, have been reported in SiC. However, most of the previous works were focused on high voltage aspects of the devices, and the high speed switching aspects of the SiC unipolar devices were largely neglected. In this paper, we report on the static and dynamic characteristics of our 4H-SiC DMOSFETs. A simple model of the on-state characteristics of 4H-SiC DMOSFETs is also presented.

Impact of Package Parasitics on Switching Performance

2016 ◽  
Vol 858 ◽  
pp. 1057-1060 ◽  
Author(s):  
Konstantin Kostov ◽  
Jang Kwon Lim ◽  
Ya Fan Zhang ◽  
Mietek Bakowski
Keyword(s):  
High Speed ◽  
Electromagnetic Compatibility ◽  
Power Devices ◽  
Power Module ◽  
Negative Effects ◽  
Power Transistors ◽  
Switching Power ◽  
Switching Performance ◽  
Current Sharing ◽  
High Speed Switching

The package parasitics are a serious obstacle to the high-speed switching, which is necessary in order to reduce the switching power losses or reduce the size of power converters. In order to design new packages suitable for Silicon Carbide (SiC) power transistors, it is necessary to extract the parasitics of different packages and be able to predict the switching performance of the power devices placed in these packages. This paper presents two ways of simulating the switching performance in a half-bridge power module with SiC MOSFETs. The results show that the parasitic inductances in the power module slow down the switching, lead to poor current sharing, and together with the parasitic capacitances lead to oscillations. These negative effects can cause failures, increased losses, and electromagnetic compatibility issues.

High-Speed Switching Method of MOSFETs Using Switching Assist Auxiliary Circuit

2013 ◽  
Vol 133 (12) ◽  
pp. 1186-1192
Author(s):  
Toshihiko Noguchi ◽  
Tomohiro Mizuno ◽  
Munehiro Murata
Keyword(s):  
High Speed ◽  
Switching Method ◽  
High Speed Switching ◽  
Auxiliary Circuit

scholarly journals A Comparative Study of GaN HEMT and Si MOSFET-Based Active Clamp Forward Converters

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4160
Author(s):  
Xiaobin Li ◽  
Hongbo Ma ◽  
Junhong Yi ◽  
Song Lu ◽  
Jianping Xu
Keyword(s):  
Comparative Analysis ◽  
Power Density ◽  
Load Condition ◽  
High Electron ◽  
Power Devices ◽  
Voltage Range ◽  
Gan Hemt ◽  
Active Clamp ◽  
Forward Converters ◽  
Bus Voltage

Compared with conventional forward converters, active clamp forward (ACF) converters have many advantages, including lower voltage stress on the primary power devices, the ability to switch at zero voltage, reduced EMI and duty cycle operation above 50%. Thus, it has been the most popular solution for the low bus voltage applications, such as 48 V and 28 V. However, because of the poor performance of Si MOSFETs, the efficiency of active clamp forward converters is difficult to further improved. Focusing on the bus voltage of 28 V with 18~36 V voltage range application, the Gallium Nitride high electron-mobility transistors (GaN HEMT) with ultralow on-resistance, low parasitic capacitances, and no reverse recovery, is incorporated into active clamp forward converters for achieving higher efficiency and power density, in this paper. Meanwhile, the comparative analysis is performed for Si MOSFET and GaN HEMT. In order to demonstrate the feasibility and validity of the proposed solution and comparative analysis, two 18~36 V input, 120 W/12 V output, synchronous rectification prototype with different power devices are built and compared in the lab. The experimental results show the GaN version can achieve the efficiency of 95.45%, which is around 1% higher than its counterpart under the whole load condition and the same power density of 2.2 W/cm3.

scholarly journals Modeling the Excess Velocity of Low-Viscous Taylor Droplets in Square Microchannels

Fluids ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 162 ◽  
Author(s):  
Thorben Helmers ◽  
Philip Kemper ◽  
Jorg Thöming ◽  
Ulrich Mießner
Keyword(s):  
High Speed ◽  
Process Intensification ◽  
Continuous Phase ◽  
Channel Cross Section ◽  
Optimization Approach ◽  
Mean Flow ◽  
Bypass Flow ◽  
Wall Film ◽  
Proposed Model ◽  
The Mean

Microscopic multiphase flows have gained broad interest due to their capability to transfer processes into new operational windows and achieving significant process intensification. However, the hydrodynamic behavior of Taylor droplets is not yet entirely understood. In this work, we introduce a model to determine the excess velocity of Taylor droplets in square microchannels. This velocity difference between the droplet and the total superficial velocity of the flow has a direct influence on the droplet residence time and is linked to the pressure drop. Since the droplet does not occupy the entire channel cross-section, it enables the continuous phase to bypass the droplet through the corners. A consideration of the continuity equation generally relates the excess velocity to the mean flow velocity. We base the quantification of the bypass flow on a correlation for the droplet cap deformation from its static shape. The cap deformation reveals the forces of the flowing liquids exerted onto the interface and allows estimating the local driving pressure gradient for the bypass flow. The characterizing parameters are identified as the bypass length, the wall film thickness, the viscosity ratio between both phases and the C a number. The proposed model is adapted with a stochastic, metaheuristic optimization approach based on genetic algorithms. In addition, our model was successfully verified with high-speed camera measurements and published empirical data.

scholarly journals Mechanism Analysis of Dynamic On-State Resistance Degradation for a Commercial GaN HEMT Using Double Pulse Test

Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1202
Author(s):  
Wei Wang ◽  
Yan Liang ◽  
Minghui Zhang ◽  
Fang Lin ◽  
Feng Wen ◽  
...  
Keyword(s):  
Gradual Increase ◽  
Dynamic Resistance ◽  
Mechanism Analysis ◽  
Pulse Test ◽  
Gan Hemt ◽  
Resistance Degradation ◽  
Dielectric Model ◽  
Leaky Dielectric Model ◽  
State Resistance ◽  
Stress Voltage

The dynamic on-resistance (RON) behavior of one commercial GaN HEMT device with p-GaN gate is investigated under hard-switching conditions. The non-monotonic performance of dynamic RON with off-state voltage ranging from 50 to 400 V is ascribed to the “leaky dielectric” model. The highest normalized RON value of 1.22 appears at 150 and 200 V. The gradual increase and following maximum of dynamic RON are found when the device is exposed to a stress voltage for an extended stress time under 100 and 200 V, which is due to a much longer trapping time compared to detrapping time related to deep acceptors and donors. No obvious RON degradation, thanks to the suppressed trapping effect, is observed at higher VDS. From the multi-pulse test, the dynamic RON is seen to be insensitive to the frequency. It is demonstrated that the leakage, especially under source and drain contact, is a key issue in the dynamic resistance degradation.

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