What the 80 Ohm impedance means for your signal line
The ACM3225-800-2P-T001 is a 2-line common mode filter rated at 80 Ohms impedance at 100 MHz. That impedance value tells you the filter's effectiveness at the switching noise frequencies typical of DC-DC converters and digital buses — 80 Ohms at 100 MHz provides moderate common-mode attenuation for signal lines where you need to suppress conducted EMI without distorting the differential signal. The 400 mA continuous current rating with a maximum DC resistance of 150 mOhm means the filter's self-heating stays low at rated load — the voltage drop across the filter is 60 mV at full current, which is negligible for a 20 V signal or power rail.
Obsolete — sourcing through independent channels
TDK has marked the ACM3225-800-2P-T001 as obsolete.