In this paper, a new non-isolated full soft-switching step-up DC/DC converter is introduced with a continuous input current for renewable energy applications. The use of a Three-Winding Coupled-Inductor (TWCI) along with a Voltage Multiplier (VM), enables the proposed converter to enhance the voltage gain with lower turns ratios and duty cycles. Also, a lossless regenerative passive clamp circuit is employed to limit the voltage stress across the power switch. In addition to Zero Current Switching (ZCS) performance at the turn-on instant of the power switch, the turn-off current value is also alleviated by adopting a Quasi-Resonance (QR) operation between the leakage inductor of the TWCI and middle capacitors. Moreover, the current of all diodes reaches zero with a slow slew rate, which leads to the elimination of the reverse recovery problem in the converter. Soft-switching of the power switch and all the diodes in the proposed converter significantly reduces the switching power dissipations. Therefore, the presented converter can provide a high voltage gain ratio with high efficiency. Steadystate analysis, comprehensive comparisons with other related converters, and design considerations are discussed in detail. Finally, a 160 W prototype with 200 V output voltage is demonstrated to justify the theoretical analysis.