I'm redesigning a board (details here) which uses analog Hall Effect sensors to measure magnet proximity, relying on output swings in the tens of millivolts, and uses a comparator to set a distance threshold.
In my redesign, I added a ground plane which didn't exist in the first version. The magnet is in front of the sensor, and the ground plane would be behind it, so the ground plane won't be in between the two.
The question is whether the proximity of a ground plane could effect the Hall Effect sensor sensitivity.
I could pull the ground plane away from the sensors a bit and still leave it behind other components, or I could eliminate it entirely. The current generation of boards has worked fine without one, but it seemed like a generally good idea to add one in the redesign until I got worried about altering the magnetic field.
Any thoughts?
Google has mostly failed me. One stack exchange discussion and one TI support forum discussion both make me think that the ground plane shouldn't be an issue since the plane is behind the sensor and the magnet isn't going to move terribly quickly. Two internet opinions don't amount to much though - I'd love to have a few more from people I trust.
Thanks!
In my redesign, I added a ground plane which didn't exist in the first version. The magnet is in front of the sensor, and the ground plane would be behind it, so the ground plane won't be in between the two.
The question is whether the proximity of a ground plane could effect the Hall Effect sensor sensitivity.
I could pull the ground plane away from the sensors a bit and still leave it behind other components, or I could eliminate it entirely. The current generation of boards has worked fine without one, but it seemed like a generally good idea to add one in the redesign until I got worried about altering the magnetic field.
Any thoughts?
Google has mostly failed me. One stack exchange discussion and one TI support forum discussion both make me think that the ground plane shouldn't be an issue since the plane is behind the sensor and the magnet isn't going to move terribly quickly. Two internet opinions don't amount to much though - I'd love to have a few more from people I trust.
Thanks!