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Topic: Pin protection on Arduino Due (Read 1 time) previous topic - next topic

dammien

Hello,

It seems that the SAM3X is less "robust" than the ATmega2560, and more subject to "accident", as:
- the operating voltage is 3.3V
- max current per pin is.. I don't remember exactly, but about 10ma
- in a general way no voltage outsite [-0.3 3.6V] should be applied

So I would like to use a "standard protection" on most of my pins, and I am interested in how you handle this.
Personally I have considered Zener diode 3.3V + Resistor 1kohm, on each pin.

But I realised that a standard (Zener) diode allows voltage as low as -0.8V, which is less than -0.3V....I suppose this is a problem?
So what do you suggest ?

thanks

DuaneB

On a related note, what would be the impact of including onboard series current limiting resistors on the DAC Outputs ?

There are a few of use that have blown these outputs through accidents of one type or another, however as the DAC output is almost always going to be going into some sort of an amplifier, I cannot see the inclusion of a current limiting resistor having any negative effect while providing protection against a range of common mistakes.

Duane B

rcarduino.blogspot.com

dammien

Hi DuaneB,

Indeed on the DAC outputs I will apply the same kind of protection : Zener 3.3V + R1000.

When I read your sentence I understand that this resistor protection would have a "negative effect" on other pins... I don't really see why ! (I mean, for most of the pins).


dammien

Hi,

Are there other opinion ?
How do you protect your pins ?


Grumpy_Mike

Quote
How do you protect your pins ?

I don't connect them to anything silly.  ;)

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