SRR4028-3R9Y is a shielded SMD power inductor from the Bourns SRR4028 series, designed for use in DC/DC converters and power supply applications. It features an inductance of 3.9 µH at 100 kHz with ±30% tolerance, a maximum DC resistance of 60 mO, and a self-resonant frequency of 56 MHz. The inductor supports an RMS current rating of 1.72 A and a saturation current of 1.5 A, with a maximum height of 3.0 mm. Operating temperature ranges from -40°C to +125°C, and the component is RoHS compliant. Common applications include portable communication equipment, camcorders, and LCD TVs where compact, efficient power conversion is required.