AVR-Chat

See that wire on your scope probe?  That is an antenna, get rid of it.
 Take of the probe clip (witches hat) and wrap a bare wire around the
metal ground sleeve.  Probe again using this wire to ground, it should
be as short as possible, less than an inch.  I bet things look different.

Rich
--- In AVR-Chat@yahoogroups.com, "magzky02" <magzky02@...> wrote:
>
> usually, bypass capacitors are placed at all vcc pins of ic's and are 
> layouted as near as posible to filter out voltage ripples...i tried to 
> measure the ripples using digital scope and it was around 300mV...but 
> i think my scope is not accurate since i get a 300mV ripples even when 
> my probe is not connected or connected to ground...my question is, 
> What is the tolerable voltage ripples? there is this called embeded 
> capacitance where in the VCC plane has embeded capacitance.By using 
> this, the .1 uF bypass capacitors are elliminated...Any idea on how to
> compare its performance with the one with .1 uF bypass capacitors?
> regards
> 
> mago
>