Time-Based Sensor Interface Circuits in CMOS and Carbon Nanotube Technologies

The evolution of electronics towards compact and highly energy-efficient systems requires joint efforts in developing both innovative system architectures and novel devices. Recent developments show that time-based sensor interfaces yield highly-digital architectures, which are compatible with advanced silicon CMOS at highly-scaled technology nodes. Advancements in CMOS time-based sensor interfaces show that new circuit techniques can help to increase performance and robustness. Furthermore, these architectures have successfully been implemented in carbon nanotube technology, a promising technology to further reduce the energy consumption in electronics. In addition, CNTs are excellent candidates to be functionalized as sensors, and can potentially improve the energy efficiency of sensors and sensor interfaces for future autonomy-demanding applications. This paper presents an overview of time-based sensor interfaces implemented in CMOS and CNT technologies, allowing for scalable and robust designs. Several CMOS and VLSI-compatible CNFET-based sensor interface circuits have been fabricated and validated through measurements, demonstrating the feasibility of these solutions.