Integration of low voltage DC sources with a load/DC microgrid is realized using a high gain DC-DC converter. Research attempts are made to develop a high gain DC-DC converter with an improved efficiency at reduced cost and size. In this paper, two new topologies with multistage extendable feature are introduced. These topologies utilize a switch-diode-inductor-capacitor (SDLC) network. The first topology uses ten components including two semiconductor switches. The second topology is derived by adding a diode and a capacitor additionally to the first topology. Hence, the voltage gain is improved and the component stress is reduced. Hence, the efficiency is improved. The proposed converters use a fewer components for extending the stage. Theoretical analysis of the presented converters is done for both continuous and discontinuous modes of operation. A laboratory prototype of 380 V, 50 kHz, 200 W, is fabricated, tested in the lab to validate the theory proposed. Continuous input current with lesser ripple, reduced switch stress, high voltage gain and n-stage structure are the attractional features of the proposed converters.