Common mode inductance, as the name suggests, is designed to attenuate and filter common mode noise in power systems. The key parameters of a common mode choke are rated current (to ensure that the component does not overheat during application), impedance frequency relationship (to ensure optimization to attenuate the required frequency), isolation voltage (to ensure that board level requirements are met between the line and neutral point), and safety isolation (to ensure that safety requirements for terminal applications are met). It is important to remember that common mode chokes cannot be saturated in applications (under normal use), as their design is to ensure that the line and return current are balanced.