How decoupling capacitors for an IC are calculated?

[sita]

Hi friends,

How the decoupling capacitors values are arrived at?

If for example, if they need 10 no of 22uF,0805 capacitors, and 2 no of 330uF bulk capacitors. My doubts are:-

1. How did they arrived at the capacitor values?
2. no of capacitors? like can I replace 10 no of 22uF capacitors with a 220uF capacitor?
3. What is the need for specifying package size, like can I use 0603 instead 0805?

4. Why and how much will be the impact, if we place capacitors in a distance more than that is allowed or nearer?

5. If anyone has some good technical notes, can you pls send?
Thanks, Sita

 

[Nora]

The book Integrity Issues and Printed Circuit Board Design by Douglas Brooks has a whole chapter on this.
Nora

 

[Kral]

sita,
I hope these attachents help.

 

[sita]

Thanks Kral & Nora for your valuable information. I shall go through your documents.

Regards,
Sita