SLYA080 july   2023 TMAG5273

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Problem with Mechanical Knobs and Rotary Encoders
  5. 2Using 3D Hall Sensor for Angle Measurement
  6. 3On-Axis and Off-Axis Test
    1. 3.1 On-Axis Test
    2. 3.2 Off-Axis Test
  7. 4Push-Button Knob Function Test
  8. 5Summary
  9. 6References

Using 3D Hall Sensor for Angle Measurement

TI offers several different types of Hall-effect sensors: switches, latches, single-axis linear, and 3D linear sensors. Linear Hall sensors output analog or digital signals, and when the strength of the external magnetic field changes, the output also changes. Unlike single-axis sensors, 3D linear sensors can use the magnetic field data from all three directions to calculate angle and magnitude. An integrated angle calculation engine (CORDIC) provides full 360° angular position information for both on-axis and off-axis angle measurement topologies, as seen in Figure 2-1. The angle calculation is performed using two user-selected magnetic axes. The three axes of sensitivity of a 3D linear Hall-effect sensor are defined as shown in Figure 2-2.

GUID-20230622-SS0I-0ZSW-WQCS-FKPFDTLK940T-low.svg Figure 2-1 On-Axis and Off-Axis Angle Measurement
GUID-20230622-SS0I-TSQT-486M-QMFZXDHQGXDZ-low.png Figure 2-2 3D Linear Hall-Effect Sensor Axis