Technical Training Adlsong SMPS Topologies The Buck Converter Buck Buck Converter Step Down Voltage Regulator Buck State 1: S is on, the inductor current rises linearly: State 2: S is off, the inductor current decreases linearly: di L =Vo dt diL (Vin ?Vo)D Vo(1? D) ? L L in =V ?Vo ?I pk = ?I pk = LfS LfS dt Volts Second Balance: Vo = DVin, D = Ton/ T V ? I = V ? I , I = I = I /D in in o o in L o