FDC2214EVM: Active Shield

Ronald Ng

Prodigy 40 points

Part Number: FDC2214EVM

Hello,

How can I drive the active shield on the FDC 2214?

Thank you,

Ron

over 7 years ago

0 Kristin Jones93 over 7 years ago

TI__Genius 17440 points

Hi Ron,

The active shield should be a buffered version of the INxA pin. The signal should be buffered by an external amplifier with a gain of 1.

Regards,

0 Ronald Ng over 7 years ago in reply to Kristin Jones93

Prodigy 40 points

Thank you for the clarification. I have the following sensor configuration:

Right now the toil coil is connected to INxA, and the bottom coil is connected to INxB. My idea is that as the ground (blue) moves in one direction (up), the signal change in INxA and INxB will be the same but in different directions. I can do a ratiometric measurement and get a stronger signal. Is this set up correct? Or should the top and bottom coil be connected to different channels and the ratiometric analysis done in post processing

0 Kristin Jones93 over 7 years ago in reply to Ronald Ng

TI__Genius 17440 points

Hi Ron,

Are you using a PCB coil for your LC tank? Or are you using coils instead of a copper pad/pour for your capacitive sensors?

Regards,

0 Ronald Ng over 7 years ago in reply to Kristin Jones93

Prodigy 40 points

The coils are instead of the copper pad for the capacitive sensor

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FDC2214EVM: Active Shield