Abstract: We are proposing to develop a SiC DC-DC power electronic interface for driving a stepper motor, which is capable of operating at high temperature (>400oC). We propose to use a non-inverting buck-boost (NIBB) power converter to convert battery voltage to a fixed DC link. This work takes account of detailed design considerations on the power stage consisting of (i) a switching circuit and (ii) SiC gate drivers with minimized parasitics and false turn-on protection. For the voltage gain regulation purpose, an analog-to-digital conversion interface along with a digital control logic will be designed and implemented in our research. In the Phase 1 program we will design and fabricate key components of the SiC DC-DC converter. These key components are a SiC CMOS Oscillator for providing switching to the SiC power devices. We will also design and fabricate the power switching devices integrated onto a single die, as well as the MOSFET gate driver circuit which applies current to the MOSFET power switches. All these circuits will be fabricated in SiC to take advantage of the wide bandgap semiconductor’s ability to operate at high temperatures. In addition to the semiconductor itself, it is necessary to have interconnects and contacts that can also withstand high temperatures. We are adopting earlier techniques involving TaSi2 to our CMOS process to achieve a complete high temperature process. These high temperature methods will be applied to fabricated test structures and components of the DC-DC converter.
High temperature SiC based power converters have wide applications in space (both inside and outside the spacecrafts), especially with respect to high temperature environments such as Venus and solar probes. The high temperature operation of SiC obviates the need for significant cooling, thus reducing the weight and volume of related electronics leaving more room for scientific payloads and reducing the cost. Applications include actuators, motors, inverters and power supplies.
High temperature electronics is potentially a huge market. SiC can operate at temperatures in excess of 400°C, which is beyond that of silicon. Applications for SiC-based electronics include furnaces, jet engines, rocket engines, and automobiles, including their exhaust systems. SiC electronics also obviate need for large cooling systems, reducing weight and form factor.