Characterization of Silicon Carbide Differential Amplifiers at High Temperature

This paper reports the characterization and modeling of differential amplifiers constructed using integrated 6H-Silicon Carbide (SiC) depletion-mode n-channel JFETs operating at temperatures up to 450degC, along with off-chip passive components. The 3-stage amplifier has a differential voltage gain of -50 dB and a unity-gain frequency of -200 kHz at 450degC, limited by test parasiticus. With further improvements in the related interconnect technology, the JFET technology reported here would enable analog sensor interface circuits operating at temperatures as high as 600degC for use in data acquisition from high-impedance microsensors.