arve9066
Member level 2
I was trying to understand the noise in switiching regulators and took 8192 samples of a 5V DC supply at 5Khz. If I calculate the 8k point FFT of this sequence, divide the absolute value by 8192 and square the expression, I will get the power right? It comes out as 14dB approximate. If I connect the dc supply then to a 50 ohm spectrum analyzer, would I see 14dB at zero frequency or 10*log10(5*5/50) = -3dB?