The Insertion loss or attenuation data filters can be found within the individual datasheets. They can help in choosing a suitable filter from the available options. Curve A shown here indicates Differential Mode attenuation while curve B indicates Common Mode attenuation. As an example, two almost identical filters are compared here, standard FN2030-10-06 and enhanced performance type FN2030N1-10-06 with higher Cy values. At typically critical frequency band of 150kHz to 5MHz, FN2030N1-10-06 can offer up to 20dB higher attenuation compared to standard FN2030-10-06 on curve B. The superimposed attenuation curves of the two filters is showing performance enhancement in general for the filter with higher Cy values.