Re: [opendiag] problem...

On Mon, Aug 28, 2000 at 08:40:26AM +0000, Sami wrote:
> Hi again,
>
> My optoisolator is Sharp PC817,
> There is a datasheet about it in:
>
> http://ns10.sharp.co.jp/ecg/pc/pc817/pc817-fea.html
>
> Could it be that this optoisolator is not good enough
> for this use?

The maximum spec quoted (18us) for rise/fall time does not have nearly
enough bandwidth for this application! I would suggest trying one of
the other recommended parts. I also had success with a plain 4n25,
although it was also beyond the 4n25's spec, I was lucky, and I have no
idea how reliable it would be in the real world.

You can test whether your isolators have sufficent bandwidth by repeating
the test I described in a previous post.

Regards,

Jeff

 
Received on Mon Aug 28 10:04:16 2000