Design, fabrication, and characterization of ultralow current operational-amplifier in the weak inversion mode in XFAB-XT018 technology

A 1.8V, 932 nA, rail-to-rail CMOS operational amplifier operating in the weak inversion regime in order to amplify the output signal of an air pressure sensor is presented. The two main parts of the ASIC are the beta-multiplier current source and the two stage amplifier. The layout has been drawn considering the matching techniques and the chip was fabricated and further characterized and measured.