Effects of Control-FET Gate Resistance on False Turn-on in GaN Based Point of Load Converter

2018 ◽  
Author(s):  
Naga Babu Koganti ◽  
Shankar Dhakal ◽  
Roshan L. Kini ◽  
Michael R. Hontz ◽  
Raghav Khanna
Keyword(s):  
Turn On ◽  
Gate Resistance

Design and Gate Drive Considerations for Epitaxial 1.2 kV Buried Grid N-on and N-off JFETs for Operation at 250°C

2010 ◽  
Vol 645-648 ◽  
pp. 961-964 ◽  
Author(s):  
Jang Kwon Lim ◽  
Mietek Bakowski ◽  
Hans Peter Nee
Keyword(s):  
Threshold Voltage ◽  
Doping Concentration ◽  
Channel Length ◽  
Channel Width ◽  
Temperature Range ◽  
Turn On ◽  
Switching Losses ◽  
Order Of Magnitude ◽  
Gate Resistance

The 1.2 kV 4H-SiC buried-grid vertical JFET structures with Normally-on (N-on) and Normally-off (N-off) design were investigated by simulations. The conduction and switching properties were determined in the temperature range from -50°C to 250°C. In this paper, the characteristics of the N-on designs with threshold voltage (Vth) of -50 V and -10 V are compared with the N-off design (Vth=0). The presented data are for devices with the same channel length at 250°C. The results show that the on-resistance (Ron) decreases with increasing channel doping concentration and decreasing channel width. The presented turn-on, Eon, and turn-off, Eoff, energies per pulse are calculated under the switching conditions 100 A/cm2 and 600 V with a gate resistance of Rg=1 . For the two N-on designs the total switching losses, Esw=Eon+Eoff, differ less than 30% with Wch 0.7 m. With Wch=0.5 m the switching losses of N-off design are almost one order of magnitude higher than those of the N-on design with Vth = -50 V.

Fast Switching with SiC VJFETs - Influence of the Device Topology

2010 ◽  
Vol 645-648 ◽  
pp. 933-936 ◽  
Author(s):  
Rudolf Elpelt ◽  
Peter Friedrichs ◽  
Jürgen Biela
Keyword(s):  
Dynamic Behavior ◽  
Current Flow ◽  
Drift Region ◽  
Active Device ◽  
Lateral Direction ◽  
Fast Switching ◽  
Turn On ◽  
Flow Through ◽  
Gate Resistance

Since SiC VJFETs are believed to offer extremely fast turn on and turn off processes it is important to understand how these transients are tailored by the layout. Regarding the basic layouts two main topologies are under investigation today – structures with the well known SIT layout with purely vertical current flow and lateral vertical concepts where the current flow through the channel is in lateral direction and the vertical current flow takes place in the drift region only. In this paper we will focus on differences in the electric characteristics of both structures and the relation of the dynamic behavior to the topology and the layout of the switches. For the analysis, 1200V VJFETs based on the two basic topologies were manufactured having approximately the same total and active device area. It turns out that the SIT switches under investigation suffer from a high internal gate resistance in the p-doped layers and a relatively high gate drain capacitance.

scholarly journals Extraction of Junction Temperature of SiC MOSFET Module Based on Turn-On dIDS/dt

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1951 ◽  
Author(s):  
Delei Huang ◽  
Guojun Tan ◽  
Chengfei Geng ◽  
Jingwei Zhang ◽  
Chang Liu
Keyword(s):  
Printed Circuit Board ◽  
Field Effect Transistors ◽  
Rogowski Coil ◽  
Circuit Board ◽  
Oxide Semiconductor ◽  
Junction Temperature ◽  
Driving Voltage ◽  
Factors Affecting ◽  
Turn On ◽  
Gate Resistance

In this paper, a method of extracting the junction temperature based on the turn-on current switching rate (dIDS/dt) of silicon carbide (SiC) metal-oxide semiconductor field effect transistors (MOSFETs) is proposed. The temperature dependence of dIDS/dt is analyzed theoretically, and experimentally to show that dIDS/dt increases with the rising junction temperature. In addition, other factors affecting dIDS/dt are also discussed by using the fundamental device physics equations and experiments. The result shows that the increase of the DC-link voltage VDC, the external gate resistance RG-ext, and the decrease of the driving voltage VGG can increase the temperature sensitivity of the dIDS/dt. A PCB (printed circuit board) Rogowski coil measuring circuit based on the fact that the SiC MOSFET chip temperature and dIDS/dt is estimated in a linear way is designed to obtain the junction temperature. The experimental results demonstrate that the proposed junction temperature extracting is effective.

Electrical Characterization of 1.2 kV-Class SiC MOSFET at High Temperature up to 380°C

2016 ◽  
Vol 858 ◽  
pp. 885-888 ◽  
Author(s):  
Yuichiro Nanen ◽  
Masatoshi Aketa ◽  
Yuki Nakano ◽  
Hirokazu Asahara ◽  
Takashi Nakamura
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Electrical Characterization ◽  
Transfer Time ◽  
Static Characteristics ◽  
Power Mosfets ◽  
Turn On ◽  
Switching Losses ◽  
Gate Resistance

Dynamic and static characteristics of SiC power MOSFETs at high temperature up to 380°C were investigated. Investigated devices have exhibited a behavior as a normally-off MOSFET even at such high temperature as 380°C. Temperature dependence of the MOSFET characteristics are reported in this paper, such as threshold voltage (VTH), on-resistance, internal gate resistance, and turn-on and turn-off losses (EON, EOFF). EON decreases and EOFF increases with increased temperature. Temperature dependence of switching losses is affected by transfer time of VDS, which was mainly determined from VTH.

Spurious Turn-On inside a Power Module of Paralleled SiC MOSFETs

2016 ◽  
Vol 2016 (1) ◽  
pp. 000379-000384
Author(s):  
Zichen Miao ◽  
Khai D. T. Ngo
Keyword(s):  
Input Voltage ◽  
Large Network ◽  
Power Module ◽  
Turn On ◽  
Switching Energy ◽  
Power Modules ◽  
Nominal Condition ◽  
Symmetry Number ◽  
The One ◽  
Gate Resistance

Abstract Silicon carbide (SiC) dice are often paralleled to realize power modules with high-current rating. Owing to the large network of interconnect (parasitic) impedances, terminal waveforms could appear benign while the dice experience detrimental fault currents generated by spurious cross-turn-on. This paper will quantify the non-uniform distribution of current stress and switching energy among the dice, as well as the penalty caused by cross-turn-on, versus layout symmetry, number of dice, gate resistance, input voltage, and load current. Cross-turn-on currents inside a module increase the high-side switching energy and total switching energy by 44% and 20%, respectively, at 800 V / 300 A. Peak cross-turn-on current of the symmetrical module is only 16% of that of asymmetrical module at nominal condition. Symmetrical layout greatly decreases the cross-turn-on currents without increasing the total switching energy. Four modules are constructed based on the asymmetrical layout to explore how number of dice influences cross-turn-on and switching energy. Peak cross-turn-on current and switching energy of the six-die module are 134% and 36% higher than those of the one-die module, respectively. Severity of cross-turn-on soars as number of dice increases.

Switching Characteristics of SiC-MOSFET and SBD Power Modules

2006 ◽  
Vol 527-529 ◽  
pp. 1289-1292 ◽  
Author(s):  
Masayuki Imaizumi ◽  
Yoichiro Tarui ◽  
Shin Ichi Kinouchi ◽  
Hiroshi Nakatake ◽  
Yukiyasu Nakao ◽  
...  
Keyword(s):  
Pulse Method ◽  
Switching Loss ◽  
Power Losses ◽  
Switching Speed ◽  
Turn On ◽  
Switching Condition ◽  
Igbt Modules ◽  
Power Modules ◽  
Switching Characteristics ◽  
Gate Resistance

Prototype SiC power modules are fabricated using our class 10 A, 1.2 kV SiC-MOSFETs and SiC-SBDs, and their switching characteristics are evaluated using a double pulse method. Switching waveforms show that both overshoot and tail current, which induce power losses, are suppressed markedly compared with conventional Si-IGBT modules with similar ratings. The total switching loss (MOSFET turn-ON loss, turn-OFF loss and SBD recovery loss) of SiC power modules is measured to be about 30% of that of Si-IGBT modules under the generally-used switching condition (di/dt ~250A/μs). The three losses of SiC modules decrease monotonically with a decrease in gate resistance, namely switching speed. The result shows the potential of unipolar device SiC power modules.

Ubiquinone-BODIPY nanoparticles for tumor redox-responsive fluorescence imaging and photodynamic activity

2021 ◽  
Author(s):  
Byunghee Hwang ◽  
Tae-Il Kim ◽  
Hyunjin Kim ◽  
Sungjin Jeon ◽  
Yongdoo Choi ◽  
...  
Keyword(s):  
Fluorescence Imaging ◽  
Selective Activation ◽  
Turn On ◽  
Intracellular Environment ◽  
Redox Responsive ◽  
Photodynamic Activity

A ubiquinone-BODIPY photosensitizer self-assembles into nanoparticles (PS-Q-NPs) and undergoes selective activation within the highly reductive intracellular environment of tumors, resulting in “turn-on” fluorescence and photosensitizing activities.

After "After the Turn On, What?", What?

1973 ◽  
Vol 18 (12) ◽  
pp. 626-627
Author(s):  
EDWARD A. JACOBSON
Keyword(s):  
Turn On
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