FDC1004 - what is the conversation range parameter meant for?

prithivi raj

Other Parts Discussed in Thread: FDC1004

Hi,

In capacitance to digital converter, I'm not able to find out for what the input capacitance range in plus/minus limits of pf farad. At what time we need to consider that parameter. if anyone knows, please let me know.

over 8 years ago

0 Joseph Wu over 8 years ago

TI__Guru* 97875 points

Prithivi,

What device is this question for? Is this for one of the FDC parts, I can move this to the capacitive sensing forum. Let me know exactly what device this is meant for, and I'll move the post.

Joseph Wu

0 prithivi raj over 8 years ago

Intellectual 355 points

whether it is the maximum range that i can measure ?

0 prithivi raj over 8 years ago in reply to Joseph Wu

Intellectual 355 points

FDC1004

0 Joseph Wu over 8 years ago in reply to prithivi raj

TI__Guru* 97875 points

Prithivi,

I've moved this post to the Capacitive Sensing Forum and I've also re-titled this post to say FDC1004. I'm sure you'll be able to find an answer here.

Joseph Wu

0 Rachel Liao over 8 years ago

TI__Expert 6480 points

Hi Prithivi,

Please take a look at the FDC1004 datasheet. It mentions that the input capacitance range is +/-15pF.

Thanks,

Rachel

0 prithivi raj over 8 years ago in reply to Rachel Liao

Intellectual 355 points

Then can't we measure more than 15pf of capacitance. if i want measure for example an 80nf, whether it is possible with this or not?

0 Rachel Liao over 8 years ago in reply to prithivi raj

TI__Expert 6480 points

Hi Prithivi,

No, you would not be able to measure 80nF.

Thanks,
Rachel

0 prithivi raj over 8 years ago in reply to Rachel Liao

Intellectual 355 points

but one of the TI employee only replied me past threads like our FDC can measure upto 0.25uF

see the below link:
e2e.ti.com/.../526082

then why not it can't measure 80nF?

0 Rachel Liao over 8 years ago in reply to prithivi raj

TI__Expert 6480 points

Hi Prithivi,

That is for the FDC2x1x series, not the FDC1004 device. You can go to our FDC product page for more information.

Thanks,

Rachel

0 prithivi raj over 8 years ago in reply to Rachel Liao

Intellectual 355 points

Thank you,
Almost we procured some samples. it is ok. then i can be sure that i can measure +/- 15 pf from the reference capacitor. right?

0 Rachel Liao over 8 years ago in reply to prithivi raj

TI__Expert 6480 points

Hi Prithivi,

By reference capacitor, do you mean the CAPDAC? If so, then yes, you are correct.

Thanks,
Rachel

0 prithivi raj over 8 years ago in reply to Rachel Liao

Intellectual 355 points

ya.... then will i be able to measure 80nf +/-15pf if i kept the CAPDAC value as 80 nf...

0 Rachel Liao over 8 years ago in reply to prithivi raj

TI__Expert 6480 points

Hi Prithivi,

No, the maximum CAPDAC value is 96.875pF as stated on the datasheet - it's a programmable offset. Please take a look at the datasheet for more information.

Thanks,

Rachel

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FDC1004 - what is the conversation range parameter meant for?