Hi All
I have designed a differential VCO at 0.15u tech. I simulated the design by gradually increasing the control voltage and got oscillations where the oscillating frequency is increasing with the increase in the control voltage.
but the oscillating swing decreases at low control voltages.
I have attached the simulation result pic.
Please look into and tell whether the simulation results are what they are supposed to be.
Any kind of inputs will be highly appreciated.
Hi All
I really apologise if my earlier post was not clear enough.
Here is the differential cell that I am using for my circuit. It is a ring oscillator design. I am also confused as to what should be the input voltage at the Vcp terminal in the differential cell. Presently I am keeping it at a constant voltage.