MSP430FR2533: capacitive sensing interference

Hello Lucifer,

thanks  for using our technology for your project.

Is there anything special question you need an answer, or just get my opinion on the general layout?

I don't know if you already have, but I would suggest to have also a view in our existing TI Designs and more specific to following TI Design

Please let me know if that helps or you have additional question.

I would suggest to use the Mutual mode like you see on the TI design, but depends on other application related parameters like overlay thickness etc.

Regarding the NFC, I would suggest to move the antenna as far as possible from the electrodes to the edge of the board.

How is the electrode on top connected to the pin, I can not see a via on the top layer

What is the white circle in the center of the electrodes?

For the layer usage, as far as I can see it follows most of our recommendations.

- TOP Layer

                Electrodes and hatched GND with about 1.5mm clearance +       NFC antenna

- L1         use for routing all the capacitive signals. RX and TX

                May be used for some power lines (NO clock signals)

- L2         full hatched GND

                Can be used for some non-clock signal routing

- Bottom              Component and digital routing

Please check the information above and let me know if you have additional questions.

Happy to support.

Regards

Kostas

Hallo Lucifer,

I have not heard back from you.

Did the information above helped to clarify / answer the questions?

Any additional help needed?

Please let me know.

Thanks

Regards

Kostas

Lucifer,

thanks for the response.

In case of a keypad, I would also suggest to check the BOOSTXL-CAPKEYPAD design which will help you to optimize the layout.

I would also suggest to think about using mutual electrodes.

What is the planed overlay material and thickness?

Best regards

Kostas