Sub-10nW, 73dB gain, inverter-based digital OTA with C-Muller input stage and novel CMFB for enhanced performance in IoT applications

This work presents a novel digital OTA based on inverter gates and capable to operate with supply voltages as low as 0.3 volt. The input stage of the proposed amplifier relies on C-Muller stages which are accurately controlled by a novel common mode feedback loop. The topology is designed in a 180 nm CMOS technology by TSMC and achieves a voltage gain as high as 73 dB with a power consumption lower than 6.9 nW. Post-layout simulation results show better figures of merit than similar digital-based topologies. Such characteristics make the proposed OTA ideal for analog applications in IoT systems and biomedical devices.