Prototyping and ESD

Archive
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Do you take into consideration ESD when you design Gadgeteer modules and mainboards? I have seen only one product made by GHI that is using TVS diodes for USB interface protection, apart from that it looks like there is no protection used.

I doubt that users are generally wearing wrist straps when they are dealing with Gadgeteer products.

Also, there are different ESD ratings, some ICs offer, for example, 2kV protection for all of their pins but suggest using additional protection if pins could be externally accessible.

I am in a process of creating a new Gadgeteer module, so I would appreciate any advises, insights, guidelines etc.

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The first board we 've designed was based on EMX. We didn’t care so much about ESD. Board controls some relays, it uses USB, ETH, Anolog and digital IO’s, One Wire… The major problem was concerning USB. Most of the time USB CDC was failing when a relay switches. The problem was that this was unrecoverable unless rebooting the EMX. We decided to use TVS diode from Wurth Electronik a ferrite from the same company according to their design rules without any success… Thus we don’t use USB CDC anymore

Now the board is based G400, I still add TVS diode and a ferrite on USB even if it is not used, and I have added clamp diodes and a PTC fuse on each analog IO’s.

I hope this will save some modules…

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@ leforban - Was your board directly accessible to the end user? In other words, could she/he touch the board?

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When we talk about end users yes everything is possible. However I have only observed failures and damaged devices due to bad wiring, shortcuts… To my opinion none of damaged devices was due to ESD ( may be one or two (see picture of metal case) in 3 years and an hundred of devices in the field).

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But will the G400 withstand EMP bursts when the Russians come?

Can we use Raptors in defense of freedom? :smiley:

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@ mtylerjr - Where will they come?

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Hopefully not New Zealand!

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@ mtylerjr - Why do I think of Kim Dotcom when I hear the words “freedom” and “New Zealand”? ;D Anyway, that is way out of topic…

So, does anybody else want to share their approach to ESD handling for Gadgeteer products?

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I can’t say that Ive heard of her, sorry.

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It would be good to have GHI design tips to handle ESD and bad wiring.

I have try to test the clamp diode and a fuse but I didn’t see anything usefull, the zener seems not regulate at 3.3V and I can apply what I want on channel, nothing happens… :’(

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That’s what I was hopping to get, but no luck yet.

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:whistle:

let’s wait and see if an electronic guru will visit this post…

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just announced : Transim - Home

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