This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DRV5032: Magnetic orientations to trigger switch at some distance

Part Number: DRV5032

DRV5032FA SOT-23 


We are coming along both the horizontal and vertical direction. As shown in the figure.
The magnet is being oriented differently, we are testing different parameters to see if we can trigger the switch at a specific distance. 

1) how sensitive is the switch to a zero crossing line?

2) Is the hall switch being triggered at a specific location (i.e. the center) or is it being triggered along the surface of the chip?

3) Lastly, How does the polarity play a factor? Does the chip take the net field if both N and S are present?

  • Stephan,

    Thank you for your questions.  Hopefully I can help resolve your concerns here. DRV5032FA is an omnipolar switch with a maximum threshold of +/- 4.8 mT.  Meaning that you may present a B Field with positive or negative magnitude greater than 4.8 mT to guarantee the switch will toggle.

    The device is only sensitive to the field component that is travelling orthogonal to the face of the package.  Since it is omnipolar, it does not matter if that is from top to bottom (negative), or bottom to top (positive).  

    The threshold to trigger the device, BOP, will have some variation.  For this device the minimum magnitude required to trip the device is 1.5 mT, and the maximum may be as high as 4.8 mT.  In any system it is safest to design around the maximum threshold to guarantee the switch will always be triggered.

    BRP is the release point for the switch, which is intentionally lower than BOP.  This built in hysteresis prevents spurious toggling due to minor variations in magnet position to help make the system more reliable.  While BRP may be as low as 0.5 mT, it will never be more than 3 mT lower than BOP.

    For a bit more clarity, the output behavior is shown here

    The exact location of the sensor within the package is shown here. 

    In the event that multiple magnets are close enough to influence DRV5032FA, then we will expect that each magnet's field will start to interact with each other.  You asked about both a north and south pole near the sensor.  Depending on how these magnets are oriented, the resulting field at the sensor may be stronger or weaker.  A lot depends on the geometry of the scenario, and I cannot predict exactly what you will observe.  However, if the resulting field is less than BOP the device will not trigger, and if it had already triggered before the second magnet is presented then it is possible that the resulting field will be less than BRP and the device will release.  It is also conceivable that the resulting field might be greater and no transition would be detected at all.