This paper presents a complete mathematical design of the main components of the 2 kW, 54V direct current (DC)–DC converter stage, which can be used as the second stage of the two stages of alternating current (AC)–DC telecom power supply. In this paper, a simple inrush current controlling circuit to eliminate the high inrush current, which is generated due to a high input capacitor at the input side of the DC-DC converter, is proposed, designed, and briefly discussed. The proposed circuit is very easy to implement in the lab using a single metal–oxide–semiconductor field-effect transistor (MOSFET) switch and some small passive elements. PSIM simulation has been used to test the power supply performance using the value of the designed components. Furthermore, the experimental setup of the designed power supply with inrush current control is built in the lab to show the practical performance of the designed power supply and to test the reliability of the proposed inrush current mitigation circuit to eliminate the high inrush current at initial power application to the power supply circuit. DC–DC power supply with phase shift zero voltage switching (ZVS) technique is chosen and designed due to its availability to achieve ZVS over the full load range at the primary side of the power supply, which reduces switching losses and offers high conversion efficiency. High power density DC–DC converter stage with smooth current startup operation, full load efficiency over 95%, and better voltage regulation is achieved