Electronics design and prototyping

Silicon Carbide Based Power Electronics and Virtual Design Platform

Silicon Carbide (SiC) is a promising new material for high power high temperature electronics applications. SiC Schottky diodes are already finding wide acceptance in designing high efficiency power electronic systems. Design of efficient Silicon Carbide based power systems requires a thorough knowledge of the physics of operation of SiC power devices, their thermal behavior, and calibrated compact models that can be included in industry standard simulation tools such as SPICE and MATLAB Simulink. Unique aspects of 4H-SiC based devices such as interface trap states, incomplete ionization, transition region, surface roughness and Coulomb scattering mobility need to be understood and incorporated in the device models to carry out accurate modeling and simulation.

"–Unique Challenges in Modeling–

Calibrated compact models of SiC devices for industry-standard simulation tools, such as SPICE and MATLAB Simulink, are necessary. Accurate modelling is challenging due to some unique aspects of 4H-SiC based devices: A higher density of interface trap states, incomplete ionization, transition region, surface roughness and Coulomb scattering mobility all need to be understood and incorporated in the device models."

Our SiC Power Electronics Virtual Design Platform enables modeling and simulation of SiC devices and circuits using a multi-tiered approach. We first link experiments to physics based models and analytical expressions. We then use those models and experimental data to create behavioral and/or SPICE models for SiC devices. Finally these models are used in circuit and system simulations. This platform provides a very crucial and economically indispensable link between SiC power device manufacturers (CREE, Infineon, etc.) and commercial (GM, Ford, etc.) and military (General Atomics, General Dynamics, Raytheon, etc.) power electronics system manufacturers.

"–CoolCAD Tools Expand Design Capabilities for power modules and SiC–

In the energy industry, where power and efficiency are of utmost importance, and cost of product is many times dictated by design and experimental testing, extensive use of CAD tools in design of new power electronics will not only reduce development cost, but will also significantly reduce time-to-market for Silicon Carbide based electronics."

Our previous NSF SBIR project titled “Development of Silicon Carbide Power Device and Circuit CAD Tools and Prototyping of SiC Based Power Converters for Hybrid Vehicles and Power Electronic Applications” enabled us to initiate the development of this Virtual Design Platform for power modules. We developed CAD tools for SiC power DMOSFET and IGBT device design, mixed-mode and SPICE based CAD tools for power converter circuits, and used them to demonstrate the viability of SiC power converters by building a prototype power converter system using SiC power devices.

Currently, we extend and improve this capability with the support of the US Army Research Laboratory and the US Office of the Secretary of Defense. The improvements include an addition of a SPICE library for all commercially available SiC power MOSFETs and most of diodes. We also build an extensive thermal library for use in conjunction with these power components and other power module passives and circuit components. The ultimate goal is to provide an improved electrical and thermal simulation capability for power module designs, especially for those that use the nascent SiC power components.

"–CoolSPICE Power–

The platform enables comprehensive design which self-consistently employs physics-based behavioral descriptions, SPICE models, thermal management and electromagnetic effects. This provides a vertically integrated and predictive system design from the device to the module levels. The enabling platform is then used to create customer specific prototypes for key high-performance SiC power systems."

Our partner the U.S. Army Research Laboratory is supporting and assisting us in the design of this software tool, and will also act as test sites for the beta version. We anticipate to have the software ready for early release soon.

Comparison of the power conversion efficiency of a 300W SiC DC-DC converter and a 300W Silicon DC-DC converter.
Thermal map of a 1200V 20A 4H-SiC DMOSFET in a TO-247 package mounted on an aluminum heat sink while being used in a 300W DC-DC converter.
SiC Power Electronics Virtual Design Platform