[SI-LIST] Re: Basic question on power plane capacitance

Assuming that you are measuring while the board is unpowered and 
unpopulated, the variables are the actual thickness, and composition of 
the dielectric layer.  If you have some IC attached to the polygon all 
bets are off.

Steve.

Mikhail Matusov wrote:
> Hi all,
>
> I have a small polygon in a plane layer of a multi-layer PCB. There is a 
> solid ground plane underneath it and the top signal layer above. I have 
> calculated from the basic plane capacitance equation that the plane 
> capacitance for this polygon should be in the range of 420 pF. However, I am 
> measuring 890 pF with one meter and 1 nF with another. I was wondering what 
> am I doing wrong?
>
>
> Thanks,
> /Mikhail 
>
> ------------------------------------------------------------------
> To unsubscribe from si-list:
> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
>
> or to administer your membership from a web page, go to:
> http://www.freelists.org/webpage/si-list
>
> For help:
> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>
>
> List technical documents are available at:
>                 http://www.si-list.net
>
> List archives are viewable at:     
>               http://www.freelists.org/archives/si-list
>  
> Old (prior to June 6, 2001) list archives are viewable at:
>               http://www.qsl.net/wb6tpu
>   
>
>
>   


-- 
Steve Weir
IPBLOX, LLC 
150 N. Center St. #211
Reno, NV  89501 
www.ipblox.com

(775) 299-4236 Business
(866) 675-4630 Toll-free
(707) 780-1951 Fax


------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
http://www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field


List technical documents are available at:
                http://www.si-list.net

List archives are viewable at:     
                http://www.freelists.org/archives/si-list
 
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu

Other related posts: