Hall, GMR or SIN/COS? Choosing Motor Feedback for PMSM Controllers

FOC needs to know where the rotor is. There are three common ways to tell it.

Hall sensors (ABC). Three digital sensors give six position states per electrical revolution. Cheap and robust, and the most common on e-motorcycle motors. The controller interpolates between states with a PLL; at very low speed, resolution is limited.

GMR encoders (ABZ). Giant-magnetoresistive encoders output quadrature pulses with much finer resolution. They give smoother low-speed torque and better NVH, at moderate extra cost.

SIN/COS. Analog sine and cosine signals give continuous, high-resolution position and are common on higher-power motors. They need careful shielding and wiring.

Sensorless. Above a certain speed, the controller can estimate position from back-EMF. It is a useful fallback, but less suited to full-torque launch from standstill.

What the T-Series supports

• All models: Hall ABC or GMR ABZ.
• T-1500 and T-2200: also SIN/COS.
• Sensored + sensorless dual mode with automatic fallback if the sensor fails.
• Sensor + PLL fusion and online parameter identification for an accurate motor model.

Wiring tip: use shielded cable for Hall/encoder harnesses, with the shield grounded at the controller end only.

Not sure which your motor uses? Ask our engineers.