This is one of the decoupling caps between VCCINT 1.8v & GND.

As you can see, the 1.8v dips down to 1.625.  This creates havoc with the processing 
inside the Altera EP20K200E which has clocks
running at 133MHz, 125MHz, 95MHz, & 24MHz.

16KB
ftp://ftp.point-lab.com/quartus/Public/ProtelUsers/NoiseVcc18-2ns.png
14KB
ftp://ftp.point-lab.com/quartus/Public/ProtelUsers/NoiseVcc18-4ns.png

Here is my current decoupling caps for the 1.8v.

4 x 0.1uf smd 0805 ceramic.
3 x 470uf electrolytic.

See the problem?

I originally had 32 x 0.1uf, but some rush work with cut & paste at one time about 2 
month ago left me with this to work with.

I need a temp fix where I only have 4 sets of access points around the APEX part with 
nice Vias to 1.8v.

I can't get my hand on the Wima caps, any other solutions, or, recommendations?

____________
Brian Guralnick
[EMAIL PROTECTED]
Voice (514) 624-4003
Fax (514) 624-3631





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