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Can FDC2xxx use analog mux for multicahnnel interface?

ttd

Mastermind 8600 points

Dear Technical SUpprot Team,

I have a question about FDC2xxx.

Can FDC2xxx use analog mux for multicahnnel interface?

LDC can use multi channel with analog mux like following 16-button KeyPad.

http://www.tij.co.jp/tool/jp/TIDA-00509

Best Regards,

y.i

over 9 years ago

0 Yibo Yu over 9 years ago

TI__Expert 8050 points

Dear y.i

Yes. FDC2xxx uses a similar core as LDC161x/131x, so their functionalities are similar.

Best regards,
Yibo

0 ttd over 9 years ago in reply to Yibo Yu

Mastermind 8600 points

Dear Yibo,

Thank you for your answer.
I unserstand that it is possible to use FDC2xxx with analog mux.

Do you have any information like TI design and Application note?

Best Regards,
y.i

0 Maikel Muller over 9 years ago in reply to Yibo Yu

Prodigy 160 points

Hi Yibo,

Actually in the "Do and Dont's" in the data sheet (page 46) it is mentioned that the FDC does not support hot-swapping of sensors, for example by using external multiplexerrs.

Maikel

0 Yibo Yu over 9 years ago in reply to Maikel Muller

TI__Expert 8050 points

Hi Maikel,

Thank you for raising this point.

The reason it's not recommended is that if a large capacitive plate holds a lot of charge, hot-swapping it could potentially damage the FDC. So this may not be feasible for some application.

To y.i,

I would say it is possible, but only do it with extra caution.

Regards,
Yibo