FDC2214: Need to be Shielded from Random Magnetic Field (Stepper Motor, DC Motor)

specia special

Part Number: FDC2214
Other Parts Discussed in Thread: FDC1004

Tool/software:

Hi Guys,

I've tried to implement this sensor for an application with a stepper motor behind the PCB, which is right on it I have to put the FDC2214 IC.

Any suggestion how to shield magnetic field of the motor? it affected something like spike noise on FDC2214 data reading. I guess the spike noise is caused by magnetic field of the motor, since yesterday I've tried to take off the motor the issue didn't appear (even the motor is not being energized, magnetic field stays)

Thanks,

Specia

8 months ago

0 Eddie LaCost 8 months ago

TI__Mastermind 43330 points

Hello Specia,

If you are using single ended mode, you could switch to a differential configuration. You can also add a shield to minimize the intereference from the motor. This is touched on in the datasheet, section 8.1.1 and 8.1.2. There are also some details in the thread linked below regarding the active shield implementation.

https://www.ti.com/lit/ds/symlink/fdc2214.pdf

https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/792437/fdc2214-shield-implementation

Also, you may want to consider the FDC1004 which includes an integrated active shield.

https://www.ti.com/product/FDC1004

0 specia special 7 months ago in reply to Eddie LaCost

Prodigy 40 points

Eddie,

Seems like impossible to use a differential configuration since we have ever tested like that and cannot meet our expectations (the SNR especially).

Good news, it turns out that we are having grounding issue with the mechanical parts (a lot of segment parts), all the mechanical parts should be connected to DC ground (or maybe EARTH) with good connection.

All the best,
Specia

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FDC2214: Need to be Shielded from Random Magnetic Field (Stepper Motor, DC Motor)