Complex High-Temperature CMOS Silicon Carbide Digital Circuit Designs

The need for dependable digital circuitry with the capability to operate reliably in high-temperature environments has been increasing drastically in applications such as automobile, aerospace, oil exploration, and power electronics. However, wide temperature swings significantly alter the threshold voltage of individual transistors, which adversely affects circuit timing in traditional synchronous designs. Such timing changes may in turn violates the setup and hold times of the clocked components, leading to potential circuit failure. This paper presents a complex digital integrated circuit design methodology using both synchronous and asynchronous logic for comparison in a young silicon carbide (SiC) design process developed by Raytheon UK. Seventeen circuits were designed, fabricated, and tested with results showing correct operation at temperatures at and above the target temperature of 300 °C.