SLYA092 June   2025 TMAG3001

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Z-Axis Pressing Offset Issue in 3D Linear Hall Sensor
    1. 2.1 Root Cause of X, Y Offsets in Z-axis Pressing Action
  6. 3The Z-Axis Pressing Detection Method
    1. 3.1 General Introduction of Proposed Method
    2. 3.2 Software Slew Rate Detection
    3. 3.3 Hardware Threshold Detection and Interrupt
    4. 3.4 Latching Method
      1. 3.4.1 Implementation of Two-Level Detection Method
    5. 3.5 Test Result
  7. 4Summary
  8. 5References

3.1 General Introduction of Proposed Method

In general, this detection method uses a hardware threshold interrupt and software slew rate or absolute value detection to reduce the influence caused by the Z-axis pressing action in the X and Y axes. Figure 3-1 shows the magnetic flux change in the Z-axis during the Z-axis pressing process. The magnetic flux change along the Z-axis is similar to an exponential function. In order to detect the pressing action as soon as possible, this method applies two-level magnetic field detection.

The Magnetic Flux Change in Z-axis Pressing ActionFigure 3-1 The Magnetic Flux Change in Z-axis Pressing Action