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DRV5023: Reverse polarity protection for 24V power supplied DRV5023 Hall Sensor

Jamel Meharzi
Prodigy 40 points
Part Number: DRV5023

Hello everyone, 

I am currently designing a sensor using DRV5023BIQDBZT Hall Sensor from TI.

We need to protect the sensor as much as we can from anything that could occur during manufacturing or installation process, because it is used in a safety device.

I see in the datasheet that it has integrated reverse polarity protection up to -22V. In my application, the sensor is powered with 24V. So a reverse polarity would cause the reverse voltage to be at least -24V, out of the limits of the sensor. 

I added a Schottky diode on Vcc rail, and a TVS between Vcc and Gnd to protect from reverse polarity and overvoltage.

I was thinking about adding a external diode in parallel with the body diode of the NMOS (between OUT and GND) so that reverse current is shared across the diodes, and excess heat generation is eliminated.

Is this a suitable solution ? Is there any reason I should not do that ? Could it influence the behavior of the sensor ?

Thank you in advance for your help.

Jamel

  • 0
    TI__Genius 15240 points

    Jamel,

    Thank you for reaching out with your question. It appears that you have taken some good steps to protect the device. You want to be sure that the output pin reverse current never exceeds 100 mA to help avoid damaging the device.  Also, as long as the output isn't taxed to produce more than 15 mA during normal operation, you should be able to drive the output appropriately.

    Since I do not know anything about the components you have selected, nor do I have any characterization data with these types of devices along with DRV5023, we cannot guarantee anything beyond what is published in the datasheet. 

    I would recommend that you carefully asses this stress with multiple units in your lab and capture pin voltages in order to evaluate the robustness of your solution.

    Thanks,

    Scott