Calculating the size of a capacitor in a sample and hold circuit

[CoolDude420]

Homework Statement

In sampling system the sample rate is 500 Ms/s with an input signal of range of 1 V
peak−peak and a clock jitter of 1 ps rms . A performance of 60 dB is required for all
signals the Nyquist baseband. Calculate its size of the capacitor.

Relevant Equations

Analog-to-Digital Conversion by Marcel Pelgrom Book

First, I calculate the jitter power with an equation given in the book

Next, I calculate the signal power

Now, I know that SNR = Psignal/(Pjitter + PthermalNoise),

However, I seem to be getting a negative value for the thermal noise power?? My plan was to use this thermal noise power and equate it to kT/C to get my capacitor size. But the thermal power is negative??
What am I doing wrong?

 

[sprog]

the thermal power is negative?? What do you calculate for the SNR?

 

[sprog]

the thermal power is negative?? What do you calculate for the SNR?

your SNR is stated as 60dB, so the factor 10^(60/20) yields 1000 fold power ratio, so your scaled Pjitter is around 0.0003

0.125 - 0.0003 is positive not negative simple math mistake?