Efficiency-Oriented Envelope Analysis of a Zeta Converter for Point-of-Load Applications

This paper presents an operating-envelope-oriented modeling and design methodology for synchronous and asynchronous Zeta dc/dc converters in Point-of-Load (PoL) applications. The proposed approach incorporates conduction and switching losses associated with passive and active components in order to evaluate their influence on voltage gain, converter efficiency, semiconductor temperature, and conduction mode boundaries. An operating-envelope analysis is developed to identify suitable high-efficiency operating regions while avoiding excessive thermal stress and discontinuous conduction mode (DCM), which are important characteristics in compact battery-powered and embedded systems. Furthermore, both continuous and discontinuous conduction modes are investigated to establish converter operating limits under different loading conditions. The study also includes a comparative evaluation between asynchronous and synchronous implementations, highlighting the efficiency improvement obtained by replacing the output diode with a low- RDS MOSFET. Experimental results validate the proposed methodology, demonstrating reduced ripple levels and an efficiency above 90% under synchronous operation. Therefore, the proposed methodology provides an effective tool for efficiency-oriented design and operating-region evaluation of high-performance switched-mode power supplies (SMPS) intended for portable, embedded, and precision electronic applications.