When a designer shops for a ferrite bead for a particular EMI suppression application, typically the specification of primary interest is the component’s Impedance vs. Frequency characteristic. Most bead manufacturers will specify this value at the commonly accepted reference frequency of 100 MHz, and supplement this “one-point” spec with a typical curve showing the variation of “Z” (Impedance) vs. “f” (frequency) for a particular bead in question. With so many characteristics available for so many different applications, it can sometimes be difficult to quickly determine the best choice for a given situation. Murata’s offerings can be broadly grouped into five major areas, depending on the intended application. The resulting shape of the Z/f curve is determined by both the ferrite formulation and the geometry of the internal electrode structure.