In general, the stability of the dielectric constant (and therefore the filter capacitance value) relative to certain operating and environmental parameters deteriorates as the dielectric constant increases. The specific factors that affect the dielectric constant are temperature, voltage, frequency and time(aging).
        The three main ceramic dielectrics used in EMI filter manufacturing are often referred to as ultra-stable(NP0/C0G), stable(X7R),and general-purpose(Y5U or Y5V). Learn More