PLL- noisy powersupply tolerance

[sakthivelmurugan]

Hai friends,

I designed PLL for 6G with 50M reference clk. when i worked with ideal supply and package model the control voltage had a variation of about 3mV. But when i gave noisy supply of +/-50mv from supply, with 50MHz frequency(ie., supply as a sinusoidal wave), the control voltage varies by 19mV. Is this noisy supply of +/- 50mv is possible.., can i check like that.. but customer told that they will give supply with +/- 20mv, but noisy supply frequency dont know.

I get no problem when the noisy supply frequency is greater than 1G.

please suggest me how to proceed with...

 

[D.A.(Tony)Stewart]

Inject 100mV or more of ripple into DC using a sweep generator to test sensitivity of f & Vac vs VCO ripple.

Then you will know how much DC filtering is needed such as with ferrite beads or RC or LC or better C's.