This　paper　proposes　a　low-noise　high-voltage　rail-to-rail　operational　amplifier　based　on　BCD　process.　For　the　pro-tection　of　low-voltage　devices　in　input　stage,　this　paper　proposes　a　common-mode　voltage　following　circuit　which　not　only　realizes　the　stable　performance　of　low-voltage　input　devices　but　also　improves　the　gain　under　full　supply　voltage.　In　order　to　improve　the　response　speed　of　large　signals,　this　paper　proposes　a　dynamic　slew-rate　enhancement　technology　to　achieve　the　characteristics　of　low　quiescent　current　and　large　slew-rate.　Besides,　this　paper　optimized　the　low-frequency　noise　of　the　proposed　architecture.　The　circuit　uses　180nmBCD　process,　and　the　simulation　results　show　that　after　applying　the　above　technology,　the　supply　voltage　range　is　3.5-36　V,　the　quiescent　current　is　about　0.99　mA,　the　equivalent　input　noise　is　0.82　uVp-p,　the　slew-rate　is　15.2　V/us,　the　setting　time　is　0.66　us　and　the　open　loop　gain　is　135　dB　in　full　supply　voltage　range.　©　2024　IEEE.