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Displaying 51 - 75 of 148

High-Voltage, High-Frequency SiC Power MOSFETs Model Validation

June 21, 2007
Author(s)
Jose M. Ortiz, Tam H. Duong, Angel Rivera-Lopez, Allen R. Hefner Jr.
Simulated results for techniques used to validate the on-state, resistive load switching, inductive load switching, and high voltage depletion capacitance performance for 4H-SiC power MOSFETs are presented. The validation is performed using a script

Long-Term Stability Test System for High-Voltage, High-Frequency SiC Power Devices

February 25, 2007
Author(s)
Tam H. Duong, David Berning, Allen R. Hefner Jr., Keyue M. Smedley
This paper presents test system developed for long-term stability characterization of 10 kV Silicon Carbide (SiC) power MOSFETs and SiC diodes under 20 kHz hard switching conditions. The system is designed to operate a single power switch and a single

Modeling MEMS Microhotplate Structures With SystemC

October 25, 2006
Author(s)
Ankush Varma, Muhammad Afridi, Akin Akturk, Paul Klein, Allen R. Hefner Jr., Bruce Jacob
Designers of SoCs with non-digital components, such as analog or MEMS devices, can currently use highlevel system design languages, such as SystemC, to model only the digital parts of a system. This is a significant limitation, since it makes key system

Generalized Test Bed for High-Voltage, High-Power SiC Device Characterization

October 1, 2006
Author(s)
David W. Berning, Allen R. Hefner Jr., J J. Rodriguez, Colleen E. Hood, Angel Rivera
A generalized 25 kV test bed developed to characterize high-voltage, high-power SiC devices is described. The test bed features containment of all high voltage circuits and the device under test (DUT) within a clear plastic interlocked safety box. A fast

Recent Advances in High-Voltage, High-Frequency Silicon-Carbide Power Device

October 1, 2006
Author(s)
Allen R. Hefner Jr., Ryu Sei-Hyung, Hull Brett, David W. Berning, Colleen E. Hood, Jose M. Ortiz-Rodriguez, Angel Rivera-Lopez, Tam H. Duong, Adwoa Akuffo, Madelaine H. Hernandez
The emergence of High-Voltage, High-Frequency (HV-HF) Silicon-Carbide (SiC) power devices is expected to revolutionize commercial and military power distribution and conversion systems. The DARPA Wide Bandgap Semiconductor Technology (WBST) High Power

On-Chip Electrostatic Discharge Protection for CMOS Gas Sensor Systems-on-a-Chip (SoC)

August 1, 2006
Author(s)
Javier Salcedo, Juin J. Liou, Muhammad Y. Afridi, Allen R. Hefner Jr.
An on-chip Electrostatic Discharge (ESD) protection scheme is demonstrated for MicroElectroMechanical Systems (MEMS)-based Embedded Sensor (ES) System-on-a-Chip (SoC). The ESD protection scheme is implemented with ground-referenced multifinger thyristor

Computer-Controlled Characterization of High-Voltage, High-Frequency SiC Devices

July 1, 2006
Author(s)
Jose M. Ortiz-Rodriguez, Allen R. Hefner Jr., David W. Berning, Colleen E. Hood, S. Olcum
Silicon carbide (SiC) power devices have begun to emerge recently with a performance that is superior to that of silicon power devices. Therefore, the push to higher power and higher voltage applications also comes with it. This work addresses the need for

10 kV, 5A 4H-SiC Power DMOSFET

May 1, 2006
Author(s)
Sei-Hyung Ryu, Sumi Krishnaswami, Hull Brett, James Richmond, Anant Agarwal, Allen R. Hefner Jr.
In this paper, we report 4H-SiC power DMOSFETs capable of blocking 10 kV. The devices were scaled up to 5 A, which is a factor of 25 increase in device area compared to the previously reported value. The devices utilized 100 υm thick n-type epilayers with

Status of High-Voltage, High-Frequency Silicon-Carbide Power Devices

March 22, 2006
Author(s)
Allen R. Hefner Jr.
The emergence of High-Voltage, High-Frequency (HV-HF) Silicon-Carbide (SiC) power devices is expected to revolutionize commercial and military power distribution and conversion systems. The DARPA Wide Bandgap Semiconductor Technology (WBST) High Power

Reliability and Performance Limitations in SiC Power Devices

December 27, 2005
Author(s)
Ranbir Singh, Allen R. Hefner Jr.
Despite Silicon Carbide's (SiC's) high breakdown electric field, high thermal conductivity and wide bandgap, it faces certain reliability challenges when used to make conventional power device structures like power MOS-based devices, bipolar-mode diodes

Characterization System for Embedded Gas Sensor Systems-on-a-Chip

December 1, 2005
Author(s)
Muhammad Y. Afridi, Allen R. Hefner Jr., Colleen E. Hood, Richard E. Cavicchi, Stephen Semancik
A characterization system is presented for evaluating critical functions of a microhotplate-based embedded gas-sensor for system-on-a-chip applications. The system uses a virtual instrument interface to control parts-per-billion (ppb) gas concentration

Characterization of Normally-off SiC Vertical JFET Devices and Inverter Circuits

October 1, 2005
Author(s)
Jih-Sheng Lai, H. Yu, J. Zhang, Y. Li, Kuang Sheng, J.H. Zhao, Allen R. Hefner Jr.
A normally-off SiC JFETs has been characterized under static and dynamic operating conditions. Two application oriented inverter circuits were constructed for additional tests under soft- and hard-switching conditions. The single-phase soft-switching

Metrology for High-Voltage, High-Speed Silicon-Carbide Power Devices

April 4, 2005
Author(s)
Allen R. Hefner Jr., David W. Berning, Colleen E. Hood
Performance metrics and test instrumentation needs for emerging high-voltage, high-speed SiC power devices are described. Unique power device and package thermal measurement test systems and parameter extraction methods are introduced, and applied to

Electrostatic Discharge Protection For Embedded-Sensor Systems-On-a-Chip

October 8, 2004
Author(s)
Javier A. Salcedo, Juin J. Liou, Muhammad Afridi, Allen R. Hefner Jr., Ankush Varma
The robustness of Embedded-Sensor (ES) System-on-a-Chip (SoC) applications involves several design constrains that require a unique assessment. For example, space-efficient electrostatic discharge protection (ESD) must be provided to protect the CMOS

Compact Models for Silicon Carbide Power Devices

October 1, 2004
Author(s)
Ty R. McNutt, Allen R. Hefner Jr., Alan Mantooth, David W. Berning, Ranbir Singh
The development of compact silicon carbide (SiC) power semiconductor device models for circuit simulation is described. The work detailed herein has been used to model power Schottky, Merged-PiN-Schottky, PiN diode, and MOSFET models. In these models, the

Lumped-Parameter Thermal Modeling of an IPEM using Thermal Component Models

August 15, 2004
Author(s)
J J. Rodriguez, Allen R. Hefner Jr., David W. Berning, M Velez-Reyes, Madelaine H. Hernandez, Jorge Gonz?lez
A thermal model for the CPES IPEM Gen. II is presented. The selected approach is the simulation of the thermal behavior of an experimental IPEM testbed using the 1D finite difference method. An equivalent electrical network representation of the thermal

10 kV, 123 m O}-cm 2 4H-SiC Power DMOSFETs

August 1, 2004
Author(s)
Sei-Hyung Ryu, Sumi Krishnaswami, Michael O'Loughlin, James Richmond, Anant Agarwal, John W. Palmour, Allen R. Hefner Jr.
10 kV, 123 mΩ}-cm 2 Power DMOSFETs in 4H-SiC are demonstrated. A 42% reduction in R on,sp, compared to previously reported value, was achieved by using an 8 x 1014 cm-3 doped, 85 υm thick drift epilayer. An effective channel mobility of 22 cm2/Vs was

Mems-Based Embedded Sensor Virtual Components for SOC

June 24, 2004
Author(s)
Muhammad Afridi, Allen R. Hefner Jr., David W. Berning, Colleen E. Hood, Ankush Varma, Bruce Jacob, Stephen Semancik
The design and implementation of a monolithic MEMS-based (Micro Electro Mechanical Systems) gas sensor virtual component is described. A bulk micromachining technique is used to create suspended microhotplate structures. The thermal properties of the