Accurate modeling of buck converters with magnetic-core inductors

In this paper, a modeling approach for buck converters with magnetic-core inductors is presented. Due to the high nonlinearity of magnetic materials, the frequency-domain analysis of such circuits is not suitable for an accurate description of their behaviour. Hence, in this work, a time-domain model of buck converters with magnetic-core inductors in a Simulink^® environment is proposed. As an example, the presented approach is used to simulate an eight-phase buck converter. The simulation results show that an unexpected system behaviour in terms of current ripple amplitude needs the inductor core hysteretic behavior to be thoroughly taken into account.

I. Introduction

Electronic device main boards are usually fed by a power supply such as battery, AC/DC converters, etc. Due to the variety of voltage levels required by circuit components, voltage regulators (VRs) are interposed between the main voltage source and the chips. The resulting power-delivery network (PDN) is required to optimize power dissipation, power integrity, and occupied area.