Y5585999AB-F is a Gigabit Ethernet magnetics transformer designed for high-speed network applications. The device features four independent transformer channels, each with a 1:1 turns ratio configuration, providing galvanic isolation for differential signal pairs. Key electrical characteristics include a minimum DC inductance of 350 µH at 100 kHz with 8 mA DC bias, insertion loss ranging from 0.5 dB to 1.2 dB across the 1 MHz to 125 MHz frequency range, and a minimum return loss of 18 dB from 0.5 to 40 MHz under 100 O impedance conditions. The transformer operates reliably over a temperature range of -40°C to +85°C and provides excellent common-mode rejection of 30 dB minimum across 0.1 to 100 MHz. This component is ideal for Gigabit Ethernet interfaces, network switching equipment, and high-speed data communication systems requiring signal isolation and impedance matching.