Hall Effect v2 baseline

[arthurPV]

Hello,

I have a hall effect sensor v2 which has a baseline signal around -350mT. It reacts ok to the presence of a magnet (north and south), but gives a non zero signal when nothing is around. It gives the same signal (and same polarity) when I move it around and I flip it, so it is not reacting to an ambiant magnetic field. It looks like it is itself magnetized and detects its own magnetic field. I tried a few other hall effect sensors, one is giving 0 as a baseline, another has something like -300mT.

Is there somehting that can be done to recalibrate the sensor? Should I request a replacement for defective items?

 

Thank you for your help.

[MatzeTF]

I assume you’re talking about - 350 μT (micro Tesla) and not - 350 mT (milli Tesla).

According to the datasheet, the sensor has a quiescent output tolerance of about ± 16 % (*note). That means that the zero point of a ± 7 mT sensor can deviate by as much as ± 1.12 mT. A baseline of - 300 μT is therefore well within the specs of the sensor.

If such a deviation is unacceptable for your application, you have to implement some kind of zeroing yourself.

Large offsets are a common issue with hall effect sensors, which is why every hall-based DC current clamp meter has a “Zero” button.

*note: (V_Q_MAX - V_Q_TYP) / (V_OUT_MAX - V_Q_TYP) = 0.13 / 0.78 = 0.166666666667