In this letter, silicon carbide MOSFET-based integrated circuits have been designed, fabricated, and successfully tested from -193 degrees C (80 K) to 500 degrees C. Silicon carbide single MOSFETs remained fully operational over a 700-degrees C wide temperature range and exhibited stable I-V characteristics. The circuits that include operational amplifier (op-amp), 27-stage ring oscillator, and buffer were tested and shown to be functional up to 500 degrees C with relatively small performance variation between 300 degrees C and 500 degrees C. High-temperature evaluation of these circuits confirmed stable operation and survivability of both the ring oscillator and op-amp for more than 100 h at 500 degrees C.