90 Ohms common-mode impedance at 100 MHz — what it means for signal integrity
The ACM2012-900-2P-TL002 is a 2-line common-mode filter from TDK's ACM series, providing 90 Ohms of common-mode impedance at 100 MHz. This impedance attenuates common-mode noise on differential signal pairs — think USB, CAN, LVDS, or Ethernet differential lines — without degrading the differential signal, because the differential magnetic fields cancel in the ferrite core. The 190 mOhm maximum DCR means a 76 mV voltage drop at full current — negligible for most logic-level signals, but worth checking if the receiver threshold is tight.
This means the part is still available for existing production but is not the target for new board spins. For BOM lines already qualified with this filter, the NRND status does not trigger an immediate last-time-buy — the part remains orderable. However, any new product introduction should select an active-series alternative to avoid a future EOL-driven respin.