Today’s goal was to understand and model VCO nonlinearity, specifically in $k_{VCO}$. Rather than just have $k_{VCO}$ as a linear function, it’s actually more similar to hyperbolic tan ($tanh(x)$). While that’s an ugly function, the output is actually quite simple. Instead of just having a normal linear function, we just put limits on the positive and negative values we can get out of it. Nominally, these are nicely at $\pm1$.