1. So, it is important for me to find the right voltage to current converter which is linear so that the frequency which depends on this current, linearly relates to the current if i'm not wrong?
2. "if your Vctrl range has to get close
to Vss, that you use a closed loop buffer to impose Vctrl
on a resistor, and take the current that it took to to
that off the drain of the buffer's follower output device.
That's a voltage to current converter that's fairly linear
and as well controlled as your resistor tempco & "make"
tolerances."
Is this the voltage to current converter example that you are talking about? I'm sorry, but it sounds very complex to me since i have just started IC designing since a month or so. Can you please break it down a wee bit more?
3. I wont be designing the complete PLL, just the VCO.
4. I have seen some concepts like level shifting, rail to rail(for low voltage working), body effect of cmos (for linearity). Am i in the right path? My professor said that i should probably look into some digital circuitry which would make my life easier. What do you suggest?