SLYT867 June   2025 LDC5072-Q1 , MSPM0G1106 , MSPM0G1107 , MSPM0G1506 , MSPM0G1507 , MSPM0G1518 , MSPM0G1519 , MSPM0G3106 , MSPM0G3106-Q1 , MSPM0G3107 , MSPM0G3107-Q1 , MSPM0G3506 , MSPM0G3506-Q1 , MSPM0G3507 , MSPM0G3507-Q1 , MSPM0G3518 , MSPM0G3518-Q1 , MSPM0G3519 , MSPM0G3519-Q1 , TMAG5170 , TMAG6180-Q1

 

  1.   1
  2. 1 Introduction
  3. 2 Using a position sensor with brushless motor control
  4. 3 Incremental and absolute encoders
  5. 4 FOC motor-control techniques and requirements for encoders
  6. 5 Position sensor technologies
  7. 6 Magnetic position sensors
  8. 7 Linear position example with a 3D Hall-effect linear sensor
  9. 8 Rotary angle example with an AMR sensor
  10. 9 Inductive position sensing
  11. 10Conclusion
  12. 11Additional resources

6 Magnetic position sensors

Magnetic encoders enable a cost-efficient method to detect rotary or linear movement while providing immunity in harsh environments that may include dust, oil and water. Magnetic position sensors detect magnetic field changes, convert them into electrical signals, and generate output signals. There are a variety of magnetic position sensor technologies, including Hall-effect, AMR, tunneling magnetoresistance (TMR) and giant magnetoresistance (GMR). Table 1 lists each sensor’s benefits and drawbacks.

Table 1 Comparison of magnetic sensor technologies: Key features and specs.
Parameter Hall Effect (without a magnetic flux concentrator) Hall Effect (with a magnetic flux concentrator) AMR GMR TMR
Operation region – – Saturation Saturation Saturation
Cost Least expensive >Hall >Hall >Hall and AMR Most expensive
Angles measured XYZ XYZ XY XY XY
Angle range (degrees) 0-360 0-360 0-180
(the TMAG6180-Q1 extends to 360)		 0-360 0-360
Latency High High Low Low Low
Angle error (degrees) <1.2 1 <11 <0.61 >12 <0.62
Magnetic flux density range (limits magnetic air-gap distances) (in milliTeslas) 0-300 0-70 >20-unlimited (the TMAG6180-Q1 tolerates up to 1,000) 20-120 20-120
  1. After gain and offset calibration.
  2. After gain, offset and orthogonality calibration