Improvement of Transformerless 200W SMPS Using CUK DC-DC Converter

This paper presents the design of transformer less DC-DC converter for 200 W SMPS application. The converter circuit based on CUK topology which is basically combination of buck and boost converter topologies. The proposed converter converts input DC voltage of 50 V or less to a 5 V stable and ripple free load current. The output also is a load independent. A fast switching and low ON-resistance power MOSFETs was used to step down voltage. The power switches operated at high frequency, and the PWM control IC was used to provide the operating signal for the switch. In this paper the concept of basic Cuk converter is reviewed, subsequently the derivation of the proposed converter is presented. And the simulation results of the power circuit are analyzed and discussed.