Design of an Analog and of a Digital-Based OTA in Flexible Integrated Circuit Technology

In this paper, an Analog and a Digital-Based Operational Transconductance Amplifier (OTA) in a 800nm Indium-Gallium-Zinc-Oxide (IGZO) Thin-Film Transistors (TFT) Flexible Integrated Circuits (FlexICs) technology are presented and compared on the basis of post-layout simulations.The analog OTA (A-OTA) and the Digital-Based OTA (DBOTA) occupy a total area of 42,624μm2 and 25,207μm2, respectively and - based on post-layout Monte Carlo (MC) simulations on 100 samples operated at 3.3V with 50pF capacitive load - they achieve an average gain-bandwidth product (GBW) of 58 kHz and 86 kHz, respectively, with an average power consumption of 90 μW and 113 μW. The simulated standard deviation of the input offset voltage is 22.3mV for the A-OTA and 7.2mV for the DB-OTA while the input-referred integrated noise over the entire GBW is 8.8 μVRMS and 87 μVRMS for the A-OTA and DB-OTA respectively.