This paper presents a fully digital operational transconductance amplifier based on a floating inverter (FI-DOTA). The proposed circuit employs floating inverters for common-mode input control and ensures high energy efficiency. Schematic simulations in CMOS 180 nm demonstrate that at a supply voltage of 400 mV, the circuit achieves a DC gain of 48 dB, a gain bandwidth product (GBW) of 41.8 kHz, and a slew rate of 5.86 V/ms while consuming only 4nW of power. The design significantly improves the GBW by 49X and the slew rate by 12X compared to previous DB-OTAs, while achieving lower total harmonic distortion (THD).