This paper demonstrates an ultra-efficient recycling folded cascode (RFC) operational transconductance amplifier (OTA) as one of the cardinal blocks in most analog microsystems. Two positive feedbacks are utilized in the proposed RFC OTA to enhance the input transconductance and the output impedance. All GAA-CNTFETs are biased in the near-threshold region (V_T≈0.37 V and V_DD=±0.2 V) to reduce power consumption. The simulation results indicate that with C_Load = 5pF, the proposed RFC OTA shows 102 dB open-loop gain and 17.2 MHz unit gain-bandwidth with an ultra-low power consumption of 111.5nW and a reasonable slew rate response (17.3 V/µs). A capacitive readout circuit for micro-and nano-electromechanical systems (MEMS/NEMS) applications is suggested to assess the proposed RFC OTA's performance in practical applications. By utilizing an RC sensing feedback structure, the proposed transimpedance amplifier presents 155dBΩ gain with a 400 MHz bandwidth. Compared to the other counterparts, the proposed GAA-CNTFET-based TIA presents fascinating power savings 86% total average improvement) and 1.6 times total average gain improvement. Our simulation results accentuate that the proposed GAA-CNTFET-based RFC OTA is a powerful candidate for designing ultra-efficient MEMS/NEMS capacitive accelerometers readout circuits.

本文展示了一种超高效的循环折叠共源共栅（RFC）运算跨导放大器（OTA），它是大多数模拟微系统中的主要模块之一。在建议的RFC OTA中利用了两个正反馈来增强输入跨导和输出阻抗。所有GAA-CNTFETs在近阈值区域偏压（V _Ť ≈0.37V和V' _DD =±0.2 V），以降低功耗。仿真结果表明，在C_负载下 = 5pF时，建议的RFC OTA显示102 dB的开环增益和17.2 MHz的单位增益带宽，具有111.5nW的超低功耗和合理的压摆率响应（17.3 V / µs）。建议使用微和纳米机电系统（MEMS / NEMS）应用的电容读出电路来评估RFC OTA在实际应用中的性能。通过利用RC感应反馈结构，所提出的跨阻放大器在400 MHz带宽下呈现155dBΩ的增益。与其他同类产品相比，拟议的基于GAA-CNTFET的TIA可以节省惊人的功率，使平均总功耗提高86％，是平均总增益提高1.6倍。