This　study　presents　a　dynamic　amplifier　with　high　energy　efficiency　and　high　gain　suitable　for　a　delta-sigma　modulator　based　on　the　floating-inverter　amplifier　(FIA),　in-depth　analysis　of　the　existing　FIA　and　its　improved　structure,　and　simulation　verification.　Compared　with　other　FIA　structures,　the　proposed　amplifier　has　a　better　compromise　in　terms　of　power　consumption　and　stability,　which　was　designed　and　simulated　using　the　SMIC　180　nm　CMOS　technology.　Under　a　1.2　V　power　supply,　the　closed-loop　direct　current　(DC)　gain　and　the　output　swing　were　about　104　dB　and　+/-　380　mV,　respectively,　and　the　input-referred　in-band　noise　was　about　-100　dB　with　the　chopper　circuit.