Need to Put cap @ ring oscillator outline

[Ayyanar M]

Hi.

I need to put a load cap in the ring oscillator outline to adjust the frequency band(using switch control ). Is it possible? If yes, what kind of switch is possible to use on it?

 

[MNBahr]

Can you clarify your issue what is switch control ?

 

[Ayyanar M]

Assume if i am getting the frequency from the ring oscillator is 2GHz. Then from this ring oscillator i need 1GHz without tweaking any values inside the Ring oscillator. We can use capacitor in the output line(output signal is sine wave) to reduce the frequency. How to add this capacitor in the Outline?

 

[FvM]

Then from this ring oscillator i need 1GHz without tweaking any values inside the Ring oscillator.

What do you mean by this? To change the frequency, the capacitor needs to be connected "inside" the ring oscillator loop, as a capacitive load for one stage, or better multiple capacitors for multiple ring oscillator stages. The frequency variation capability by a single capacitor will be limited.

 

[Ayyanar M]

yes i plan to use multiple capacitor inside, but i need to switch it depends upon application(Capacitor connect or disconnect).

 

[varunkant2k]

That method may not be linear to switch across the Large Band size.
Better you generate 2Ghz from VCO and use external analog circuits to divide this frequency to the desired frequency. This method used across IC design to avoid jitters. But again using frequency divider/multiplier, you also need phase com