SLYA085 December   2023 TMAG6180-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2AMR Angle Sensing
  6. 3Calibrating AMR
    1. 3.1 Input Related Errors
    2. 3.2 Sensor Related Errors
    3. 3.3 Offset
    4. 3.4 Amplitude Mismatch
    5. 3.5 Orthogonality Error
    6. 3.6 Noise
  7. 4Summary
  8. 5References

Abstract

Anisotropic magneto-resistive (AMR) sensors are magnetic sensors that detect the direction of the magnetic field vector rather than the strength of the field. An AMR sensor determines the position of a rotating permanent magnet if the field is sufficiently strong. AMR sensors can typically only resolve up to 180°.

TMAG6180-Q1 and TMAG6181-Q1 both implement AMR sensing combined with a 2D Hall-effect latch to expand angle calculations to a full 360° for low-latency angle measurements. TMAG6180-Q1 produces outputs Q0 and Q1 which provides quadrature data for absolute angle measurements and TMAG6181-Q1 includes a turns counter function which tracks relative position even while operating in low power sleep mode. Understanding how to properly calibrate an end system when configuring these devices and possible sources of error is important.