Thank you Fvm for pointing out the unwanted usage of numbers..actually i copy pasted them from my pc calculator...right away..
Ok Let me put my question in another way..
One more question .Is n't the regulator power supply noise can be considered like the white noise??& wont the measured noise power vary with the bandwidth used to measure it??
I ve seen a lot of regulator power supplies specifying say 50mVpp ripple on their output..Measured with 20MHz bandwidth. in normal oscilloscope..Assuming a 50Ohm impedance in measurement, i want to convert this specification to dBm/Hz format..
So what is the correct way to do..
Is like the following
It is mentioned as 50mVpp in 20MHz BW
So is it like {[(50mV/ √20MHz)]² / 50 }= 2.5e-12W/Hz
So finally converting to dBm =10log(2.5e-12/1e-3)=10log(2.5e-9)= -86.05dBm/Hz
Thanks for any help