The photovoltaic interface has several requirements: a high step-up ratio with clean input and output currents, high efficiency, compact size and ease of design. A novel two-port isolated Cuk topology is proposed in this paper which addresses all of these issues. It has a partial integrated magnetic structure which enables nearly-zero ripple input and output currents along with reduction in size and weight of the passive components. The transformer isolation provides the step-up ratio. The topology also combines an active-clamp structure which allows ZVS (zero-voltage switched) turn-on with passive snubber components which allow a ZCS (zero-current switched) turn-off of the active switches. The functionality of this quasi-resonant circuit is verified by simulating a PV circuit of typical specifications.