Design of SOI CMOS operational amplifiers for applications up to 300°C

Design guidelines using two analog parameters (Early voltage and transconductance to drain current ratio) are proposed for correct operation of silicon-on-insulator (SOI) CMOS operational amplifiers (opamp) at elevated temperature up to 300°C. The dependence of these parameters on temperature is first described. A new single-stage CMOS opamp model using only these two parameters is presented and compared to measurements of several implementations operating up to 300°C for applications such as micropower (below 4 μW at 1.2 V supply voltage), high gain (65 dB) or high frequency up to 100 MHz. Trade-offs among such factors as gain, bandwidth, phase margin, signal swing, noise, matching, slew rate and power consumption are described. The extension to other architectures is suggested and the design methodology is valid for bulk as well as SOI CMOS opamps