B.2.2.1 Spurious Effects in the Second-Order Loop

In addition to the spurious effects of the first-order converter the non-linearity of the first integrator adds to the noise with a power spectral density proportional to $s\tau_0$, which eats up part of the benefits of the second-order approach. In addition to that, the potential overdrive of the first integrator limits the allowable input signal range even further (depending on a), which reduces the dynamic range and thereby the achievable SNR.