SBAA449B October   2020  – October 2021 TMAG5110 , TMAG5110-Q1 , TMAG5111 , TMAG5111-Q1

 

  1.   Trademarks
  2. 1Introduction
  3. 2Latch Response of the 2D Hall Effect
  4. 3Two Axis Sensor Consideration
    1. 3.1 Magnet Selection
      1. 3.1.1 Pole Count
      2. 3.1.2 Magnet Strength
    2. 3.2 Sensor Selection
      1. 3.2.1 Axes of Sensitivity
        1. 3.2.1.1 In-Plane Sensor Alignment
        2. 3.2.1.2 Out-Of Plane Sensor Alignment
      2. 3.2.2 Sensor Placement
        1. 3.2.2.1 On-Axis Magnetic Field
        2. 3.2.2.2 In-Plane Magnetic Field
        3. 3.2.2.3 Out-of-Plane Magnetic Field
      3. 3.2.3 Sensitivity Selection
  5. 4Optimizing for Accuracy
    1. 4.1 Optimizing Placement for Accuracy
    2. 4.2 Optimizing a Magnet for Accuracy
  6. 5Application Implementation
  7. 6Summary
  8. 7References
  9. 8Revision History

6 Summary

Two dimensional hall effect latches, such as TMAG5110 and TMAG5111, offer a practical means to measure quadrature for incremental rotary encoding applications. These devices allow the user to select which axes of sensitivity are most ideal and can then be placed On-Axis, In-Plane, or Out-of-Plane. Matching device sensitivity and phase alignment, which are common sources of error when using discrete sensors, requires very little effort due to the excellent matching and multiple axes of sensitivity available by integrating two orthogonal sensors into a single package.

The performance in these applications can be improved even further by understanding the magnetic field and how it relates to the quadrature results of a two-dimension dual Hall-effect latch. By carefully examining placement and magnet selection, it is possible to minimize the total measurement error. Having this understanding leads to an effective method for improving quadrature alignment and accuracy.

Once an alignment has been selected, it is recommended to adjust the position of the sensor along a single axis until quadrature error is minimized in a test configuration. For testing with a sensor integrated into an existing application, consider the Hall Adapter EVM which provides a miniature PCB for this purpose. If placement variation is constrained, then increasing pole count or magnet strength can also provide an alternative to minimize the total measurement error of the system.