What this 1210 common-mode choke does on a signal line
The TDK ACM3225-161-2P-T001 is a two-line signal line choke from the ACM series, filtering common-mode noise on differential signal pairs up to 160 Ohms at 100 MHz. Rated for 350 mA continuous current with a maximum DC resistance of 200 mOhm, it sits on a 20 VDC rail — typical for low-voltage digital interfaces like USB, LVDS, or CAN bus where you need to knock down conducted emissions without starving the line of current. The 1210 (3225 Metric) body with four leads is a standard footprint for rework — it lifts clean under hot air if the pad is tinned right, and the orientation mark on the top makes it hard to flip.
Obsolete — sourcing reality for the BOM line
For an existing BOM line, the supply path runs through independent surplus and broker channels where inventory is lot-specific and confirmed at RFQ. If you are qualifying a replacement, look for a 1210 common-mode choke in the same impedance band (160 Ohms @ 100 MHz) with a current rating at or above 350 mA and DCR under 200 mOhm — the footprint and pinout are standard enough that several manufacturers offer drop-in parametric matches, but each must be validated against the original's insertion loss profile.
Temperature envelope and board-fit note
Rated for -25°C to 85°C operating temperature, this choke covers indoor and most industrial ambient conditions but not extended automotive or under-hood ranges.