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PSoC™ 4 Forum Discussions

nishc_4031946
Level 1
Level 1
First reply posted First question asked Welcome!

Hi,

In one my end application where I need capacitive touch to digital conversion i'm using cy8cmbr3002, also i'm using single strand wire loop as sensor for sensing capacitive touches, it works well. This entire setup is functioning in 9V DC battery.

Now problem/issue is that when ever i touch to DC supply cables and DC battery , cy8cmbr3002 senses this touch as well. so here my point is any one have ever encountered with such issue, what could be the possible solution.

thank you.

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4 Replies
BragadeeshV
Moderator
Moderator
Moderator
First question asked 1000 replies posted 750 replies posted

Hi,

Could you please share the schematic and layout of the design?

Also please check if you have the following in place:

1. 560 ohms series resistor in capsense line?

2. Is there ground hatch pattern around the sensor?

3. Are there decoupling capacitors in power supply lines?

Generally we don't recommend single strand wire loop as touch sensor. We recommend only solid copper fill as touch buttons.

Please refer to the following document for additional information on MBR3 Capsense layout guidelines:

https://www.cypress.com/file/46366/download

Could you please let us know your application?

Regards,

Bragadeesh

Regards,
Bragadeesh
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Dear Bragadeesh,

I can not share schematic or layout as per NDA.

Also,

1. 560 ohms series resistor in capsense line? ==> Yes

2. Is there ground hatch pattern around the sensor? ==> Yes, for top and bottom side

3. Are there decoupling capacitors in power supply lines? ==>  Yes, as per design guide lines

can you share your official email where I can share some more details?, I can not share those here.

Thanks,

Regards,

Nikhil S.

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Hi,

Could you please make a solid fill for the copper pad and check if you still face the issue?

You can refer to the layout guidelines in our MBR3 capsense design guide for the button design.

https://www.cypress.com/file/46366/download

If this doesn't solve your issue, we can proceed further with the schematic or layout review.

Regards,

Bragadeesh

Regards,
Bragadeesh
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This thread has been locked due to inactivity for more than three weeks.

-Cypress Semiconductor

Regards,
Bragadeesh
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