AVR-Chat

Overshoot can also be caused by mismatched rise and fall times in the  
drivers.

You can also have capacitive coupling from the gate to the source and  
if the Vcc level of the top transistor is smaller than the driving  
signal, this can be quite serious.

I suggest that you look at commercial driver ICs. One problem is that  
most do not allow the input logic level to exceed the driver's Vcc.

Jim

On Dec 30, 2009, at 7:28 PM, mago Umandam wrote:

> OK, i'll do research on how to do that driver-load impedance matching.
>
> Thanks
>
> --- On Thu, 12/31/09, David VanHorn <microbrix@gmail.com> wrote:
>
> From: David VanHorn <microbrix@gmail.com>
> Subject: Re: [AVR-Chat] reducing signal overshoot/undershoot
> To: AVR-Chat@yahoogroupscom
> Date: Thursday, December 31, 2009, 10:20 AM
>
>
>
> On Wed, Dec 30, 2009 at 6:53 PM, tim gilbert <tim@jeminnovation.  
> com> wrote:
> > Mago,
> > You need to match your output driver to the impedance of the load.
> >
>
> Yup. And maybe reduce drive current.
>
> The over and undershoot is caused by reflections.
>
> [Non-text portions of this message have been removed]
>
>
> 



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