A　closed-loop　brain-machine　interface　requires　the　integration　of　the　neural　stimulation　and　recording　circuits　with　the　microelectrode　array.　A　challenge　for　simultaneous　neural　recording　and　stimulation　is　the　large　interference　faced　by　the　neural　amplifier　induced　by　stimulation　artifacts.　In　this　work,　front-end　circuit　design　technique　and　digital　post-processing　are　combined　to　provide　a　solution　for　fast　recovery　of　the　neural　amplifier　from　artifact,　based　on　a　signal　folding　scheme.　A　chip　integrating　the　neural　recording　and　stimulation　circuits　is　implemented　in　GF-0.18μm　CMOS　process　for　proof　of　concept.　In　-　vitro　experiment　is　conducted　using　this　chip,　showing　the　viability　of　the　proposed　design.　At　stimulation　current　levels　from　50　-　100　μA,　which　is　sufficient　for　deep　brain　stimulation,　a　faster　recovery　time　of　around　1　ms　is　achieved　with　the　proposed　neural　amplifier　compared　to　4　ms　from　conventional　one.　©　2017　IEEE.