SBAA463A january   2021  – april 2023 TMAG5170 , TMAG5170-Q1 , TMAG5170D-Q1 , TMAG5173-Q1 , TMAG5273

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
    1. 1.1 Angle Measurement With One-Dimensional Sensors
    2. 1.2 Challenges of Angular Measurements
  4. 2Benefit of Multi-Axis Sensors
    1. 2.1 Simplified Mechanical Placement
    2. 2.2 Sensitivity Matching
    3. 2.3 CORDIC Angle Estimations
    4. 2.4 Tamper and Stray Field Detection
  5. 3Angular Measurement Considerations
    1. 3.1 Sensor Alignment
    2. 3.2 Sensor Calibration
    3. 3.3 Input Referred Noise
    4. 3.4 Impact of Sample Rate
  6. 4Practical Application
    1. 4.1 Push-Button Knob
      1. 4.1.1 Evaluating Design Constraints
      2. 4.1.2 Magnet Selection
      3. 4.1.3 Prototyping and Verification
    2. 4.2 Off-Axis Design
      1. 4.2.1 Sensitivity Gain Correction
      2. 4.2.2 Accuracy Verification
  7. 5Summary
  8. 6References
  9. 7Revision History

4.1.1 Evaluating Design Constraints

To sufficiently demonstrate the performance of both the A1 and A2 variant of TMAG5170, it was determined that the input magnetic flux density should be close to full scale input for the highest range of the TMAG5170A1.

A knob with 1-in diameter was designed so that it could provide something substantial enough to manipulate while keeping the solution small enough to comfortably ship with the EVM packaging. As a result, the available opening for any magnet needed to be roughly 1/2 in.

GUID-20201211-CA0I-WHZJ-R0S8-DRR1X9JQ62R6-low.gif Figure 4-1 TMAG5170 Push-Button Knob Attachment