Flicker noise analysis

In this analysis we will also take 1/f noise into account. The 1/f noise limit can be described using the equation:

$S_{en}(f) \le S_{em,floor} ( 1 + \dfrac{f_c}{f^2} )$

Where $S_{em,floor} = 2.5 \cdot 10^{-17} V^2/Hzm^2$ and with corner frequency $f_c = 200$ kHz

We have a showstopper if the following condition is not met

$8/3 KF < S_{em,floor} L_A^2f_cC_a$

For our design, $KF = 3 \cdot 10^{-25}$, $L_A = 0.5m$, $f_c = 200 \cdot 10^3 Hz$, $S_{em,floor} = 2.5 \cdot 10^{-17}$ and $C_a = 5pF$

Filling in the values gives:

$ 8 \cdot 10^{-25} < 6.25 \cdot 10^{-24}$

Thus using this technology we have a factor of 12.8 of room left for the noise requirements.

A plot of the total input flicker noise is shown below

Using this information, we can conclude that the current technology is not a showstopper for the noise requirements