A high-frequency high-step-down converter with coupled inductor for low power applications

This paper proposed a new topology that can achieve high-step-down conversion compared with traditional buck converter. A coupled inductor is employed to extend duty cycle which is for high-step-down applications. Soft-switching of all switches can be achieved. A prototype with 24 V input 5 V/2 A output is given to verify the circuit operation. Switching frequency is up to 1.3 MHz to minimize magnetics size. The peak efficiency can reach to 87 %.