SLLSFT3 November 2025 MC121-Q1
ADVANCE INFORMATION
In motors, commutation is the process of orienting stator and rotor magnetic fields to maintain continuous rotor motion. The rotor of a single phase BLDC motor contains a permanent magnet with alternating poles. The stator has one phase winding which attracts and repels the rotor magnet poles when energized. A Hall sensor integrated in the MC121-Q1 determines which direction to drive the current through the stator winding to commutate the motor. Figure 6-11 shows an example of single-phase motor commutation using the MC121-Q1. For proper motor commutation, the MC121-Q1 must be placed between two of the stator poles with the Hall element directly beneath the rotor magnet.
The MC121-Q1 driver integrates the following functions for commutation of a single-phase BLDC motor.