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DRV5053: Low frequency noise in linear Hall effect sensors

Hans Bartling
Prodigy 20 points
Part Number: DRV5053
Other Parts Discussed in Thread: DRV5056, , DRV425

I am aiming to use a Hall effect sensor to measure slow variations of permanent magnets due to temperature. Therefore the sensor should not compensate for temperature fluctuations of the magnet such as the DRV5056 does. I have been testing two linear ratiometric hall effect sensors (among which DRV5056), but I keep suffering from low frequency noise from the Hall sensor. As far as I understand it, I could overcome this noise through chopper-stabilization and consequent low-pass filtering. The DRV5053(-Q1) mentions chopper-stabilization in the datasheet, but I am wondering whether this would solve the problem described above.

Thanks in advance for your answer.

  • 0
    TI__Mastermind 26425 points
    Hello Hans,

    Thank you for using the TI forum. Although the DRV5053 does not have the temperature compensation, it will still drift with temperature (±10%). Also, the DRV5056 is a higher precision device than the DRV5053. One possible suggestion I have for you is to isolate the magnet from the sensor so that you can change the temperature of the magnet without changing the temperature of the sensor. This way the temperature compensation will not affect you as much. (If possible for your setup).

    As for the noise you are seeing, you may want to check to see if it is around 60Hz. If so, then the noise could be coming from your power supply. You could also try powering up the device with a battery to see if the noise goes away.

    A low-pass filter on the output of the DRV5056 can also help reduce noise (if you don't need the full bandwidth).
  • 0 in reply to Mitch M
    Prodigy 20 points
    Hello Mitch,

    Thank you for your answer. In the meantime I have done additional tests and notice that the Hall sensors have 1/f noise at low frequencies. This makes filtering after the Hall sensors a lot less effective. Nothing of this sort is mentioned in the datasheet of the DRV5056. Hence I was wondering if all Hall sensors have 1/f noise and whether there is any way around it?

    Hope you can help.
    Hans
  • 0 in reply to Hans Bartling
    TI__Mastermind 26425 points
    Hello Hans,

    The chopper-stabilization in the DRV5053 should help with the 1/f noise. However, looking over your question again, I recommend that you use the DRV425 (www.ti.com/.../DRV425) for your application, which is not a Hall sensor, but a Fluxgate sensor. This is a very high-precision magnetic field sensing device with no temperature sensitivity compensation.