Analysis of a Fourth Order Step-Down Converter

In this paper, a fourth-order buck converter with higher capability to step down supply voltage is proposed. Owing to low voltage gain that ideally altercates from minimum to a maximum value near unity, this converter becomes a suitable choice for interfacing high voltage DC-supply with a low voltage application at the output. Key features of this topology include lesser switching elements with minimal switch voltage stress. The steady-state analysis of converter is discussed for continuous conduction mode of inductor current and design criteria for selecting circuit components are established. In order to regulate its load voltage, a single-loop voltage mode controller has been designed making use of the state-space average model obtained using equivalent ON and OFF switching circuits. A converter prototype test circuit is designed for 42 to 12 V, 28 W rating to verify the steady-state and dynamic performance of converter using simulation and experimental studies.