This paper proposes a closed-loop dynamic amplifier using three-stage floating inverter amplifier (FIA). The closed-loop configuration and high open-loop gain owing to the three-stage configuration ensures the gain accuracy and robustness to process, supply voltage, and temperature (PVT) variation. Moreover, careful phase compensation design enables a stable output response, resulting in fast settling. The simulation results show that the proposed circuit can reduce the closed-loop gain error to 0.4% and the error variation due to PVT variation to less than half of that of the conventional circuit.