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 42,624um2 and 25,207um2, 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 uW and 113 uW. 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 uVrms and 87 uVrms for the A-OTA and DB-OTA respectively.