Design Considerations of an Analog Voltage Mode Readout Circuit for the CMOS-SOI-MEMS Gas Sensor Dubbed GMOS.

Modern gas sensor technology is becoming an important part of our lives. Hence, there has been considerable effort over the past 25 years towards the goal of creating low-cost gas sensors by employing modern microelectronics technology to manufacture both the sensing element and the signal conditioning circuitry on single silicon chips. CMOS sensors based on CMOS-SOI-MEMS technology seemed to be a good candidate for the monolithic approach. In this study, we critically review this approach. We show the advantages of chiplet-based designs for gas sensors that are based on CMOS-SOI-MEMS technology, dubbed GMOSs. The design of a monolithic GMOS system based on the voltage mode reading of a GMOS transistor connected in a three-terminal configuration is presented and validated for the first time. This study led to the understanding that a chiplet-like design should be preferred since the sensor and the readout circuitry of traditional gas sensors exhibit conflicting technological requirements. The innovation of this work is both in the readout design that it posits and in the resulting paradigm shift.