This article introduces the ST7MC microcontroller family, which is the second generation of the 8-bit microcontroller family dedicated to driving 3-phase brushless DC motors. These microcontrollers have advantages such as high efficiency, low noise, and better reliability, and are suitable for both sensor and sensorless methods of permanent magnet brushless DC motor control.
This document details the PWM management strategies for controlling 3-phase brushless DC (BLDC) motors using the ST7MC microcontroller family. It covers the hardware integration of the motor control macrocell and explains how to configure registers for efficient motor driving.
The note specifically addresses sensorless control methods, including the classic method and the ST method, for reading Back Electromotive Force (BEMF) signals. It provides guidance on configuring the PWM manager in both voltage and current modes and discusses techniques for winding demagnetization and synchronous rectification.
The two main methods are the classic method and the ST method.
Yes, the ST7MC is able to detect the BEMF zero-crossing signal during either the PWM signal ON time or OFF time.