The CS0402-3N9J-S is an inductor with SMD (Surface Mount Device) 0402 RoHS (Restriction of Hazardous Substances) manufactured by Chilisin. It is a component that utilizes inductance, or the ability of a coil of wire to impede the flow of electrical current, to store energy in an electric field. The CS0402-3N9J-S inductor is in the size 0402, which is one of the smallest SMD packages available, measured as a 0.04” x 0.02” square. It is commonly used in a variety of electronic applications such as DC-DC converters, clock circuits, power supplies, switching regulators, and other general purpose applications. It is RoHS (Restriction of Hazardous Substances) compliant, meaning that it does not contain hazardous materials such as lead or mercury.