A 2.5 V 0.13 μm CMOS amplifier for a high-temperature sensor system

A high-temperature amplifier, designed and simulated in a 0.13 mum CMOS process, is presented. The amplifier is intended to operate in a wood chip digester used for pulp manufacture in which the ambient temperature can be as high as 180degC. Since the foundry provided modeled are valid up to 125degC, the amplifier along with its bias circuitry is simulated up to 125degC by considering a reasonable margin for the gain and gain bandwidth when temperature increases beyond 125degC. At 125degC, the amplifier has a DC gain of 69 dB, phase margin of 86deg and unity gain bandwidth of 4.13 MHz, while consuming 0.62 mW (excluding the bias circuitry) from a 2.5 V supply.