vco specifications
Helloo savithru,
first u need to maintain differential pair transistors in saturation .for that u need to have common mode level between min and max levels.for min and max values go through
Desigon of analog integrated circuits by razavi.
and for highr swings voltage drop must be choosen optimum.how ever large voltage drop may force differential pair into triode region.this may cause noise at output.
specifications depends on u r application.so no one can fix specifications.if u specify application some one may give better specifications.
if we talk abot capacitor by changing delay one can chan ge frequency of ring oscilators ,so load capacitance should be choose optimum.how ever by increasing fo tail current increases output frequency.
u can design 2.4GHz ,but r u going to work with 1.2um(or)0.12um. with 0.12um u can achieve 2,4GHz very easily.
No One can give exact (W/L) and capacitor values.if some one already did same work before may can give .In analog ic desigining every thing is depend on another so there are no fixed values. expecting fixed values is absolutely wrong.
With basic rules try to change (W/L) values for example if u need more current increase W.
and morever u r unclear about u r project first be clear what u wanna do
Best Of Luck
Rajesh Babu Madala