1 1 Abstract-This paper describes a high temperature voltage comparator and an operational amplifier in a 1.2 µm silicon carbide CMOS process. These circuits are used as building blocks for designing a high temperature SiC low-side over current protection circuit. The over current protection circuit is used in the protection circuitry of a SiC FET gate driver in power converter applications. The op amp and the comparator have been tested at 400 °C and 550 °C temperature respectively. The op amp has an input common-mode range of 0-11.2 V, DC gain of 60 dB, unity gain bandwidth of 2.3 MHz and a phase margin of 48° at 400 °C. The comparator has a rise time and a fall time of 38 ns and 24 ns, respectively, at 550 °C. The over current protection circuit, implemented with these analog building blocks, is designed to sense a voltage across a sense resistor up to 0.5 V. Keywords-comparator, op amp, current sensor, silicon carbide, high temperature electronics, wide bandgap ICs. I.K. Addington is with the

This paper demonstrates the first reported high temperature voltage comparator in CMOS silicon carbide. The comparator was designed in a 1.2 μm CMOS SiC process and has been tested for a voltage supply of 12 V to 15 V. The rail to rail voltage comparator has been tested up to 450°C with rise and fall times of 31 ns and 22 ns respectively, and positive and negative propagation delays of 108 ns and 107 ns respectively.