DCDC synchronous step-down controller, adjustable output, adjustable frequency, input voltage 4.5-24V, maximum load 30A, using QFN3x3encapsulation, adjustable frequency 300khz, 400khz and 600khz; the maximum load current is configured by the inductor DCR and external resistance; with Ultra-fast loop response speed, the suppression of output overcharge is very good when the load is switched; the inductor current sampling current limit mode is adopted to improve the system conversion efficiency; the pulse skipping mode is adaptively switched under light load to obtain higher light load conversion efficiency; features such as soft start, thermal environment, UVLO undervoltage lockout, gate driver undervoltage lockout, and overcurrent protection.