Renesas Technology

This document describes a method of commutating a 3-Phase Brushless DC (BLDC) motor using Back-EMF (BEMF) signals.

This document is intended to supplement the understanding of 6-step BLDC motor control using BEMF detection as one of many possible methods of commutation. The BEMF-detection method, as well as the Hall device method, are implemented on the Renesas YMCRPR8C25 Motor Control Evaluation kit, which provides an excellent platform for developing the algorithm for individual applications. The reader should already have some understanding of six-step commutation methods, such as Hall commutation, to provide background to the techniques described here. The reader is encouraged to first read the 6-Step Motor Drive with HALL sensor Application Note referred to in the Reference section at the end of this document.