A 300mV-Supply, 2nW-Power, 80pF-Load CMOS Digital-Based OTA for IoT Interfaces

This paper presents a power-efficient Ultra Low Voltage (ULV) Digital-Based Operational Transconductance Amplifier (DB-OTA), which uses static logic gates and processes digitally the analog input signal. Post-layout simulations in 180nm CMOS technology show that at 300mV supply voltage the circuit consumes just 2nW while driving a capacitive load of 80pF with Total Harmonic Distortion lower than 5% at 100mV input signal swing. The total silicon area is $1,426\ \mu \mathrm{m}^{2}$. The maximum energy efficiency supply for the DB-OTA and its scalability to 40nm CMOS technology node are also demonstrated.