FDC2214

Vignesh TG

Prodigy 155 points

Other Parts Discussed in Thread: FDC2214

Hello,

When I used FDC2214 EVM, why the sensor capacitance for channel 0 and 1 are showing as 16pF and 18pF initially?

Why it is showing these much capacitance initially without connecting custom sensor?

Waiting for your kind response.

Thank you and Regards,

Vignesh

over 6 years ago

0 Clancy Soehren over 6 years ago

TI__Mastermind 23810 points

Vibnesh,

Channel 0 and channel 1 come with preconnected sensors. You can snap them off and connect your own sensor if you want (or you can use channels 2 and 3).

0 Vignesh TG over 6 years ago in reply to Clancy Soehren

Prodigy 155 points

Hello Clancy Soehren,

I know to use channels 2 and 3.

My question is when I connect the FDC2214 EVM alone without preconnected sensors (removed from EVM), why the capacitance on any channel (it can be channel 0 or 1 or 2 or 3) is showing 16 to 22pF.

It should be either 0 or some few pF only. Why it is so?

Waiting for your kind response.

Thank you and Regards,

Vignesh

0 Bala Ravi over 6 years ago in reply to Vignesh TG

TI__Expert 6625 points

Hi Vignesh,
This is because of the parasitic capacitance. Depending on the sensor frequency you're trying to achieve, I would subtract the parasitic capacitance from the value of the capacitor you're trying to use.

Best Regards,
Bala Ravi

0 Vignesh TG over 6 years ago in reply to Bala Ravi

Prodigy 155 points

Hello Bala Ravi,

Thank you for your reply.

I'm getting sensor frequency of about 4.3 to 4.8 MHz. Then how much parasitic capacitance you would subtract from the value of the capacitor?

Waiting for your kind response.

Thank you and Regards,

Vignesh

0 Vignesh TG over 6 years ago in reply to Vignesh TG

Prodigy 155 points

Hello,
I'm still waiting for a response.

Thank you and Regards,
Vignesh

0 Clancy Soehren over 6 years ago in reply to Vignesh TG

TI__Mastermind 23810 points

Vignesh,

We can't say what exactly that will be. You would need to measure it.

Sensors

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FDC2214