Adum4160 + ESD Protection

Hello Yachaan,

I don't see any reason this implementation would be a problem.

MSCantrell

Thanks so much!

Here is my implementation of the above:

5aXis-USB-iso-BOB - CNCzone.com-The Largest Machinist Community on the net!

Hello Yachaan,

After seeing the entire thing, I have a couple of comments. 

1) the protection is to stop ESD and EOS from the cable being applied to the chip.  Please review whether the ESD protection should be referenced to the 5V line instead of the 3.3V line.  The configuration shown would not protect the regulator.

2) the primary USB interface looks good, your PIC is a peripheral and the upstream side is powered from the cable.

I can't read the option section, what are you doing with the other isolation and connectors?

Good luck

Hi, thanks for the interest.

1] I try to protect my PC from this board and the stepper drivers further down the line.

So it is the other way around.

I thought  i was going to show you a correction. BUT:

An app note:

Should I not get rid of the pull-up resistor at the input side? [No VDD]

Alternatively, here is two resistors at the input - how would this affect the USB setup?

2] The ADuM3440 is to protect this board from the drivers and them from each other..

I only use 3/4 of the io's on each ADuM

it is only outgoing commands.

3] almost forgot about the incoming signals from limit switches.

Also through an ADuM.

Corrected:

"The ADuM3440 is probably not the best part for limit switch application.  This part is our highest speed coupler, and we eliminated the glitch filter in favor of high throughput.  A lower cost solution would be the ADuM3400A which is slower, and has a glitch filter.  One is a drop in replacement for the other."

Here is my second application:

Under number4, alternatively.

Here only the Main controller runs on 3.3V, the rest on 5V.

It also controls the USB. You can see the the D+&D- IO's

What you don't see is the USB monitor & USB-DISC on the controller - it's lower down

I am still trying to find out how it works. I you have a suggestion, Please help.

My main Q is: is this correct to reference the ESD protection like I did?

[note that the input still depends on the firs Q's answer]

Hello Yachaan,

Yes, I think this is the correct connection for the protection devices.

The ADuM3440 is probably not the best part for limit switch application.  This part is our highest speed coupler, and we eliminated the glitch filter in favor of high throughput.  A lower cost solution would be the ADuM3400A which is slower, and has a glitch filter.  One is a drop in replacement for the other.

Good luck.

"Yes, I think this is the correct connection for the protection devices."

I am not sure witch one of the two you mean,

the one MINUS resistor & 3.3V at the input  I presume?

And what about the second application - any comment or suggestion?

PS: I see that I updated my Q's - AFTER you posted yours....

Hello Yachaan

On the upstream side, the ADuM4160 has an integrated pullup, and you would be doubling up. So definitely do not use an integrated pull-up on the upstream side.

I don't see that you need a filter on the downstream side at all. If you do use it, you need to base the integrated pullup on what the peripheral controller requires.

I would also think about protecting the 5V power line with a diode on the cable side.

Best Regards,

MSCantrell