SLYA060 August   2022 TMAG5110 , TMAG5110-Q1 , TMAG5111 , TMAG5111-Q1

 

  1.   Abstract
  2.   Trademarks
  3. Introduction
  4. System Block Diagram
  5. Key System Specifications
  6. HW Connections
  7. Software
    1. 5.1 TI-RSLK LaunchPad Software
    2. 5.2 LaunchPad Software
  8. How to Design With Hall-Effect Latches
  9. Simulation Results
    1. 7.1 Select Device Sensitivity
    2. 7.2 Select Axis of Sensitivity
  10. Performance Comparison
    1. 8.1 Speed and Direction
    2. 8.2 Power Consumption
    3. 8.3 Susceptibility to External Particles
  11. Encoder Board Schematic and Image
  12. 10Summary

Speed and Direction

The speed tests were conducted by spinning the TI-RSLK motor at the maximum speed (150 RPM). In this case, the IR encoder did not show any performance advantages in comparison to the Hall-effect based solution. The main advantage of IR sensors is their ability to sense higher speeds than typically allowed by magnetic encoders. Hall-effect sensors contain a frequency bandwidth limit you should not exceed, or else the sensor might not detect changes in the B field appropriately. Figure 8-1 and Figure 8-2 show the encoder outputs.

One of the main benefits of using the TMAG5111 is to more easily tell which direction the motor is turning. Figure 8-2 shows that when the motor is rotating in the clockwise direction, the orange signal that indicates direction is high. Figure 8-3 shows that the output pulls low when the motor spins in the counterclockwise direction. To implement direction in an IR-based solution, you must add an additional IR sensor to the system. This could potentially add more problems to the system, such as possibly increasing the the solution size, each IR sensor being unable to distinguish the source of the light signal and affecting the output of the other sensors, and increasing the power consumption.

GUID-20220705-SS0I-VS85-3V06-4BVSMNGFXPPM-low.pngFigure 8-1 IR Encoder Output.
GUID-20220705-SS0I-MTD0-SRPX-VW8FLGGW7CBM-low.pngFigure 8-2 TMAG5111 Encoder Output Clockwise.
GUID-20220705-SS0I-DRDJ-XH6C-NVLHDLDVDVLP-low.pngFigure 8-3 TMAG5111 Encoder Output Counterclockwise.