sivan_75 said:
What is the exact definition of PSRR for VCO? Is it the ratio of change of output frequency and the change of supply voltage?. In that case, the unit will be Hz/V.Is it right? How can you calculate in dBs? If some one answers, that would be fine.
The variation in VCO frequency for a change in supply voltage is called Supply pushing and expressed in Hz/V. If the PLL is expected to provide clock to a data converter, then writing this in terms of jitter addition will make sense where it takes the unit of ps. If you have a specific frequency at the power line to be worried about, then if you run a transient with that noise on the supply and plot the dft, you can infer that the frequency spur due to the supply noise is below the carrier by so much dB where it takes the unit of dBc.