Owing to the harmonic problems created by the electronic equipments in the power distribution system, the need for power factor correction is important. This paper presents a good solution for implementing a low cost, high power factor ac to dc converter for low power application with fast output regulation. A single stage converter called Integrated Buck Fly Back converter (IBFC) is used for this applications. In this both the Buck and Fly Back semi stages are operated in discontinuous conduction mode. The circuit is designed and simulated for wide input voltage, ranges from 90 - 250 Vrms, 48 V output operating at 100 kHz. The simulation is performed using PSIM© software. The closed loop control of the circuit is also analysed based on the voltage mode control strategy using a PI controller.