Ultra Low Power Read-Out Integrated Circuit Design

摘要

Carbon nanotubes (CNTs) are widely studied by the researchers in recent years, as they have small size, large strength, highly electrical and thermal conductivity. The single-walled CNT (SWNT) is readily changed in electrical resistance when exposed to gas, and has significant use in environmental monitoring, agriculture and fishing industry, chemical industry and even security. A read-out integrated circuit (ROIC) is required to detect the resistive change. In this thesis, an ultra-low power, wide dynamic detecting range and small size CMOS ROIC design is presented. This ROIC can interface wide dynamic range signal up to more than two orders (100pA-60nA) from deployable sensors using automatic gain control (AGC) unit. A novel technology of sub-threshold technique is applied in this design, which can save up to 96% (from 25.2mW to 0.89mW) power consumption comparing to the circuit operating in super-threshold. To improve the accuracy of calibrated readout current, compensation factor derived from the analysis of simulation results is finally added. The proposed circuit also has the capability to output 8 bit digital signal that can be transmitted wirelessly to the data center for further signal processing.