A class of coupled inductors based on LTCC technology

Using coupled inductors in multi-phase point of load converters is an effective way to improve system steady state and dynamic performance. Thus, package of coupled inductors for system three-dimensional integration is attracting great interest of research. This paper explores design, fabrication and analysis of planar coupled inductors based on low temperature co-fired ceramic technology. Four structures classified by winding forms and their distribution in the core are introduced and compared firstly. Then, an analytical model for approximating inductance value is derived. Two LTCC coupled inductors are fabricated and their measurement results are provided. Finally, a 12 V input, 1.8 V/40 A output two-phase interleaved buck converter is construed for testing a LTCC coupled inductor.