CY8C4125 ESD fail

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RoTs_4749531
Level 1
Level 1

Hi,

I am using 4125 with capsense feature in a desk lamp, when I do the ESD test, found something strange.

My lamp is covered by plastic shell, so ESD is not easy to access into PCB borad, So I use the ground pin on the table to release ESD charge.

It will shut down and reboot when I do this action, and will crash after several rounds.

The behavior is very similar to excite the XRES pin, but I can also do this by using a metal rod to touch the GND pad on PCB, even some other exposed pads.

Does anyone have the experince on this phenomenon?   

Regards,

Robert

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1 Solution
VenkataD_41
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hi Robert,

Can you please attach some images of your lamp?

Can you please elaborate more like where is the ground pin connected to? (images would be helpful)

If possible, please attach the schematic of your board.

The following white paper on ESD might help you.

https://www.cypress.com/documentation/white-papers/electro-static-discharge-esd-tutorial

Use TVS diodes on the pins or traces those are exposed or potential to catch ESD.

Thanks

Ganesh

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2 Replies
VenkataD_41
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hi Robert,

Can you please attach some images of your lamp?

Can you please elaborate more like where is the ground pin connected to? (images would be helpful)

If possible, please attach the schematic of your board.

The following white paper on ESD might help you.

https://www.cypress.com/documentation/white-papers/electro-static-discharge-esd-tutorial

Use TVS diodes on the pins or traces those are exposed or potential to catch ESD.

Thanks

Ganesh

RoTs_4749531
Level 1
Level 1

Hi Ganesh,

Your link is helpful.

Since this is a new project contains some new patent items, please forgive me can't provide the schematic.

After consulting my colleague, they suggest the same as you.

To add TVS and VAR on some other I/O pins to avoid the unexpected actions.

Thanks for your helping, I'll try it on the next pilotrun.

Regards,

Robert

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