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CAPSENSE™ & MagSense Forum Discussions

RoIm_4475046
Level 1
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Hi,

I am having a problem with sensors from CY8CMBR3116-LQXI.

This is on a 4 layer flex pcb.

I have two chips configured on different I2C addresses.

When I use EZ-Click to configure and test it, I get no response on several sensor channels.

Attached are the system diagnostics of both of them.

The sensor pads in the middle are non functional and the ones that show capacitance over 20cp are the ones working correctly.

Could it be something on my pcb layout?

I am attaching a screenshot of the pcb layout and gerber files.

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RoIm_4475046
Level 1
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Level 1

Actually, disregard this. It must have been something on the assembly.

I assembled another board and it works fine.

View solution in original post

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Hari
Moderator
Moderator 750 replies posted 500 replies posted 250 solutions authored
Moderator

Hello RoIm_4475046

Can you also share the schematic of the design?

Please make sure that there is a 2.2 nF capacitor on the Cmod pin.

MBR devices support sensing with Cp >5pF only. Typically, the pin capacitance is itself 3pF.

The layout seems to be correct regarding the pin to sensor connection.

There seems to be a layer that says top EMI shield. Can you please clarify what this is?

Thanks and regards

Hari

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RoIm_4475046
Level 1
5 sign-ins First reply posted First question asked
Level 1

Actually, disregard this. It must have been something on the assembly.

I assembled another board and it works fine.

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