IEC 63093-9 Ed. 1.0 b:2020

IEC 63093-9:2020 specifies the shapes and dimensions of ferrite cores for inductive components (transformers and chokes), whose the coil is typically made of multi-layer boards (or the coil is part of the motherboard), and the effective parameter values used in calculations. This document gives guidelines on allowable limits of surface irregularities applicable to planar-cores as well.