High-Temperature Switching Characteristics of 6H-SiC Thyristor

1996 ◽  
Vol 423 ◽  
Author(s):  
K. Xie ◽  
J. R. Flemish ◽  
T. Burke ◽  
W. R. Buchwald ◽  
J. H. Zhao
Keyword(s):  
High Temperature ◽  
Current Density ◽  
Operating Temperature ◽  
Time Increase ◽  
Temperature Range ◽  
Turn On ◽  
Switched Current ◽  
Switching Characteristics ◽  
Off Time ◽  
Bias Condition

AbstractA 280 V 6H-SiC thyristor has been fabricated and characterized. The switching characteristics of the SiC thyristor were investigated over a temperature range from 23 °C to 400 °C, with a switched current density of 4900 A/cm2 being observed under pulse bias condition. The thyristor has shown a dV/dt of 400 V/ms. Both the turn-on time and turn-off time increase significantly at 400 °C. The thyristor forward breakover voltage decreases by only 5% when the operating temperature is increased from 23 °C to 400 °C.

An Optically Gated InP Based Thyristor for High Power Pulsed Switching Applications

1991 ◽  
Vol 240 ◽  
Author(s):  
J. H. Zhao ◽  
R. Lis ◽  
D. Coblentz ◽  
J. Illan ◽  
S. McAfee ◽  
...  
Keyword(s):  
High Power ◽  
High Concentration ◽  
Photoconductive Switch ◽  
Turn On ◽  
Power Handling ◽  
Switched Current ◽  
Power Handling Capability ◽  
Pn Junctions ◽  
Switching Characteristics ◽  
Switch Voltage

ABSTRACTAn MOCVD grown InP based optothyristor has been fabricated and tested for high power pulsed switching applications. To increase the power handling capability, the thyristor structure has a 250 μm thick Fe doped semi-insulating (SI) InP sandwiched between two pn junctions of a conventional thyristor. The turn-on of the thyristor is controlled by optical illumination on the SI-InP which creates a high concentration of electron and hole pairs. More than 1,100 V device hold-off voltage has been observed and over 66 A switched current has been realized with a di/dt rating of 1.38×1010 A/s. The switched current as a function of switch voltage and of optical illumination power has also been studied. Comparison with the switching characteristics of a bulk SI-InP photoconductive switch clearly indicates the advantage of this optothyristor in terms of power handling capability.

A Robust SOI Gain-Boosted Operational Amplifier Targeting High Temperature Precision Applications up to 300°C

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000238-000242
Author(s):  
Alexander Schmidt ◽  
Abdel Moneim Marzouk ◽  
Holger Kappert ◽  
Rainer Kokozinski
Keyword(s):  
High Temperature ◽  
Circuit Design ◽  
Robust Design ◽  
Wide Temperature Range ◽  
Operational Amplifier ◽  
Operating Temperature ◽  
High Gain ◽  
Temperature Range ◽  
Op Amp ◽  
Operating Temperature Range

Data acquisition and signal processing at elevated temperatures are facing various problems due to a wide temperature range operation, affecting the accuracy of the circuits' references and elementary building blocks. As the most commonly used analog building block, the operational amplifier (op-amp) with its various limitations has to be enhanced for wide temperature range operation. Thereby major effort is put into maximizing signal gain and simultaneously reaching high gain-bandwidth also for high temperatures. Future robust design approaches have to consider a growing operating temperature range and increasing device parameter mismatch due to the downsizing of integrated circuits. Addressing one of the major problems in circuit design for the next decades, compensating these effects through new design approaches will have a lasting impact on circuit design. In this paper we present a high gain operational amplifier with a folded-cascode and gain-boosted input stage, fabricated in a 1.0 μm SOI CMOS process. The operational amplifier was designed for an operating temperature range of −40…300°C. Major effort was put into a robust design approach with reduced sensitivity to temperature variations, targeting high precision applications in a high temperature environment. With a supply voltage of 5 V, the maximum simulated current consumption of the op-amp is 210 μA which leads to overall maximum power consumption of 1.05 mW. The open loop DC gain of the amplifier is expected to reach a minimum of 108 dB and a unity-gain-frequency of 1.02 MHz at a temperature of 300°C. For all temperatures the phase margin varies from 55…70 degrees for a 3 pF load.

600 V -Class V-Groove SiC MOSFETs

2014 ◽  
Vol 778-780 ◽  
pp. 931-934 ◽  
Author(s):  
Yu Saitoh ◽  
Masaki Furumai ◽  
Toru Hiyoshi ◽  
Keiji Wada ◽  
Takeyoshi Masuda ◽  
...  
Keyword(s):  
Low Temperature ◽  
Oxide Layer ◽  
Room Temperature ◽  
Gate Oxide ◽  
Class V ◽  
Turn On ◽  
Switching Losses ◽  
Thick Oxide Layer ◽  
Switching Characteristics ◽  
Off Time

The authors applied a thick gate oxide layer at the trench bottoms to 600 V class truncated V-groove MOSFETs of which MOS channels were formed on 4H-SiC (0-33-8) facets and validated the static and switching characteristics. The specific on-resistance and the threshold voltage were 3.6 mΩ cm2(VGS=18 V,VDS=1 V) and about 1 V (normally-off), respectively. The breakdown voltage of the MOSFET with a thick oxide layer was 1,125 V (IDS=1 μA). The switching losses during turn-on and turn-off operations were estimated to be 105.8 μJ and 82.5 μJ (300 V, 10 A) at room temperature. The switching characteristics exhibited low temperature dependence for turn-on/off time.

Fast Switching Characteristics of 4H-SiC RESURF-Type JFET

2008 ◽  
Vol 600-603 ◽  
pp. 1095-1098
Author(s):  
Kazuhiro Fujikawa ◽  
Kenichi Sawada ◽  
Takashi Tsuno ◽  
Hideto Tamaso ◽  
Shin Harada ◽  
...  
Keyword(s):  
Power Supplies ◽  
Fast Switching ◽  
Turn On ◽  
Dc Power ◽  
Surface Field ◽  
Switching Characteristics ◽  
Off Time ◽  
Reduced Surface ◽  
Switching Devices

400V/2.5A 4H-SiC JFETs having a reduced surface field (RESURF) structure were fabricated. Measurements on the static and switching characteristics were carried out. The on-resistance was 0.86 W. The turn-on time (ton) and the turn-off time (toff) were 8ns and 10 ns, respectively. The fabricated JFETs showed low on-resistance and fast switching characteristics. 4H-SiC RESURF-type JFETs, which is a sort of lateral transistor, are preferable to a module configuration of switching devices. Moreover, they are promising for application to DC power supplies with higher efficiency and smaller size owing to their low on-resistance and fast switching characteristics.

A Solar Thermal Electrolytic Reactor for Studying the Production of Metals From Their Oxides

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
P. Krenzke ◽  
K. Krueger ◽  
N. Leonard ◽  
S. Duncan ◽  
R. D. Palumbo ◽  
...  
Keyword(s):  
Steady State ◽  
Current Density ◽  
Design Variable ◽  
Operating Temperature ◽  
Electrolytic Cell ◽  
Solar Thermal ◽  
Cell Design ◽  
Process Performance ◽  
Temperature Range ◽  
Operating Variables

A solar thermal electrolytic reactor was developed for studying at a 10 kW scale how a solar reactor’s electrolytic cell design and operating variables influence the performance of a solar process for producing metals from their oxides. Current versus voltage maps as well as current versus time for specified voltages were obtained for the electrolysis of ZnO and MgO within the temperature range of 1200–1500 K and various electrolytic cell configurations. An example of a map is presented. The data from maps and steady-state runs were used to illustrate how we quantify the influence of the cell’s operating temperature and current density on process performance. We also illustrate how one design variable, the cell’s electrolyte, influences process performance.

1700V, 20A 4H-SiC DMOSFETs Optimized for High Temperature Operation

2011 ◽  
Vol 679-680 ◽  
pp. 633-636 ◽  
Author(s):  
Brett A. Hull ◽  
Sei Hyung Ryu ◽  
Q. Jon Zhang ◽  
Charlotte Jonas ◽  
Michael J. O'Loughlin ◽  
...  
Keyword(s):  
High Temperature ◽  
Leakage Current ◽  
Entire Temperature Range ◽  
Electrical Characteristics ◽  
Switching Circuit ◽  
Inductive Load ◽  
Temperature Range ◽  
Continuous Current ◽  
Switching Characteristics ◽  
High Temperature Operation

DMOSFETs fabricated in 4H-SiC with capabilities for blocking in excess of 1700V and conducting 20A continuous current in the on-state are presented. These SiC DMOSFETs remain functional to temperatures in excess of 225°C, with leakage current at 1700V at 225°C of less than 5 A with VGS = 0V. The DMOSFETs show excellent switching characteristics, with total switching energy of 1.8 to 1.95 mJ over the entire temperature range of testing (25°C to 200°C), when switched from the blocking state at 1200V to conducting at 20A in a clamped inductive load switching circuit. The electrical characteristics are compared to commercially available Si IGBTs rated to 1700V with similar current ratings as the SiC DMOSFET described herein.

High Temperature Characteristics of 4H-SiC RESURF-Type JFET

2009 ◽  
Vol 615-617 ◽  
pp. 727-730
Author(s):  
Kazuhiro Fujikawa ◽  
Kenichi Sawada ◽  
Hitoki Tokuda ◽  
Hideto Tamaso ◽  
Shin Harada ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Junction Temperature ◽  
Positive Temperature ◽  
Switching Operation ◽  
Fast Switching ◽  
Turn On ◽  
Surface Field ◽  
Switching Characteristics ◽  
Reduced Surface

400V/2.5A 4H-SiC JFETs having a reduced surface field (RESURF) structure were fabricated. Measurements on the on-resistance, blocking and switching characteristics at high temperature were carried out. It was confirmed that the JFET has smaller dependence of on-resistance on temperature than a Si-MOSFET and positive temperature dependence of the breakdown voltage. It was also confirmed that the JFET has fast switching characteristics, that is, the turn-on and turn-off times are about 15 ns and 10 ns, at 200 °C as well as at 25 °C. A demonstration of a DC-DC converter using a module consisting of the JFET was carried out at a junction temperature of 200 °C. Stable continuous switching operation of the JFET at a junction temperature of 200 °C was confirmed.

A comparison of CeB6 and LaB6 thermionic cathodes

1991 ◽  
Vol 49 ◽  
pp. 346-347
Author(s):  
L. A. Christman ◽  
G. A. Schwind ◽  
L. W. Swanson
Keyword(s):  
Electron Beam ◽  
High Temperature ◽  
Work Function ◽  
Current Density ◽  
Operating Temperature ◽  
High Heat ◽  
Lanthanum Hexaboride ◽  
Thermionic Cathodes ◽  
Reduced Temperature ◽  
Lower Operating Temperature

In recent years lanthanum hexaboride (LaB6) has proven to be an excellent thermionic cathode material, and has become the standard for most electron beam applications. The reasons that LaB6 is superior to tungsten as a material for thermionic cathodes are that it has a low work function and low volatility at high temperature. It is also relatively insensitive to most contaminants (or can at least be thermally cleaned of most contaminants).The most important consideration in cathode performance is its volatility at the operating temperature required for achieving the required current density. The work function for clean LaB6 is 2.6 eV compared with 4.5 eV for tungsten, thus it is possible to operate the former cathode at a considerably reduced temperature compared with tungsten. The volatility is greatly reduced, not only because of the lower operating temperature, but also because LaB6 has a relatively high heat of vaporization considering its low value of work function.

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