Suggest me 20pF capacitors for a 5Mhz chip in 0.35um CMOS process

[dsj_guilin]

Hi,

I want implement some 20pF capacitors in a chip which will operate at about 5MHz. What kind of capacitor should I use? Can anyone give me some references which talk about it.

Many thanks

Added after 1 hours 16 minutes:

And the process is 0.35um CMOS.

 

[keith1200rs]

Capacitor on chip

It depends on what is important to you. You could pick the one with the smallest area, but that may have the highest stray capacitance to substrate. I assume you want floating capacitors? If so, you need to find out how much capacitance to substrate you can tolerate. Sandwich capacitors have a reasonable ratio of capacitance to stray - e.g. poly/Met1/Met2 sandwich with poly & Met2 connected.

Whose 0.35um process is it?

Keith.

 

[dsj_guilin]

Re: Capacitor on chip

Thanks Keith. I will use the TSMC 0.35um process.

 

[AdvaRes]

Capacitor on chip

You can the capacitance of the transistor. Moscaps are very usefull and easy to implement.

Cheers,
Advares.

 

[love_analog]

Re: Capacitor on chip

Before jumping with suggestions, the OP needs to clarify if he wants floating or not.

In generat, cap to ground -> moscap -> least area
floating -> need MIM, MOM or finger cap.