Considerations on Dimensional Dependence of Thin-Film Single-Layer Coreless Micro-Transformers for Digital Isolators

Novel power semiconductor devices with high withstand voltage and high-speed operation use digital isolators for isolated transmission of gate drive signals. The isolators are required to have the similar level of withstand voltage and operating speed as the power semiconductor devices. In this work, thin-film single-layer coreless micro-transformers fabricated on silicon chips are proposed for digital isolators in power switches operating at high voltage and high speed. This paper describes the dimensional dependence of the micro-transformers. Guidelines for dimensional optimization are discussed based on theoretical analysis of the relationship between transmission characteristics and the occupied area, the number of turns, and the conductor width for the micro-transformers. © 2024 The Institute of Electrical Engineers of Japan.