The NDMB242100 is an Ethernet transformer module designed to support high-speed data transmission for 1, 2.5, 5, and 10 Gbit/s Ethernet applications. It features four differential pairs (BI_DA, BI_DB, BI_DC, BI_DD) with a 1:1 turn ratio (±3%) and provides insertion loss of -2.0 dB maximum across 1–400 MHz and -3.0 dB maximum from 400–500 MHz. The module delivers return loss of -22 dB minimum at 1–100 MHz and maintains crosstalk isolation of -28 dB minimum at 1–100 MHz, with common mode rejection ratio of -30 dB minimum at 1–40 MHz. With a current rating of 960 mA per differential pair and hipot isolation of 1,500 VAC for 60 seconds, this transformer is ideal for network interface cards, switches, routers, and other high-speed Ethernet equipment requiring reliable signal coupling and noise rejection.