Design of a process variation tolerant CMOS opamp in 6H-SiC technology for high-temperature operation

A process variation tolerant silicon carbide CMOS operational amplifier intended for high-temperature operation with a tunable phase margin and unity-gain bandwidth is presented. A novel bias circuit is provided such that the voltage gain of the operational amplifier is insensitive to large threshold voltage and mobility variations. An output stage along with an adaptive biasing technique is developed to produce a full rail-to-rail output voltage swing and a low output resistance. To achieve a large phase margin in the presence of large process variations, a compensation structure using a tunable external voltage is also proposed.