The relationship between size and power dissipation in a 1-10 MHz transformer

Abstract

This paper considers the tradeoff between size and power dissipation in the design of low profile 1-10 MHz transformers with planar spiral windings. For a fixed power loss and number of conductor layers, the transformer with the smallest possible footprint can be designed by a tradeoff of core and copper loss. This paper discusses the relationship between the marginal reduction of transformer footprint, and the associated marginal increase in power dissipation and/or number of conductor layers, for the design of the smallest possible transformer.

A Systematic Approach to Modeling Impedances and Current Distribution in Planar Magnetics

“…However, the increasing skin and proximity effects and the resulted self and mutual impedances make the modeling challenging, especially when parallel windings are included. Previous modeling efforts have estimated ac resistance [8]- [12], predicted parasitics [13]- [15], estimated core losses [16]- [21], generated circuit representations [22], [23], extracted parameters by experimental measurements [24], [25], developed transmission line models [26], [27], [29]- [31], and investigated current sharing among parallel and interleaved windings [32]- [35]. These approaches have different focuses, rely on various assumptions, and sometimes are not easy to use.…”

Impedance control network resonant step-down DC-DC converter architecture

“…In order to reduce the losses, we use many layers of conduction, with 8 layers ultimately chosen. Given the dimensions of the EILP43 core set, a finished thickness of 62 mils was chosen in order to avoid any fringing effects from the air gap between the core halves [34,35].…”

Digital Controlled High Frequency Switching Mode Power System

“…The total core loss at flux densities below saturation is a sum of three loss mechanism [5]: hysteresis, residual, and eddy current. There are several curve fitting formulae used for the approximation of core loss.…”