PM1812-390J-RC is a surface-mount chip inductor designed for use in DC/DC converters, power supplies, and general applications requiring stable inductance performance. The device features a ferrite core with copper wire coil and epoxy resin enclosure, delivering 39 µH inductance with ±5% tolerance and a maximum DC resistance of 4.5 ohms. It operates across a wide temperature range from -40°C to +125°C with a maximum temperature rise of 20°C, and exhibits a self-resonant frequency of 10 MHz minimum. The inductor is RoHS compliant, offers high resistance to heat, humidity, mechanical shock, and pressure, and is optimized for automatic surface mounting with accurate dimensions. These characteristics make it ideal for compact power management circuits where reliable inductance and thermal stability are essential.