800 Ohm common-mode choke for DC power rails
The TDK ACM4532-801-2P-T001 is a 2-line common-mode filter from the ACM series, delivering 800 Ohms impedance at 100 MHz on a DC power rail up to 50 V and 1 A continuous. Packaged in a 1812 (4532 Metric) footprint with 6 leads, it filters conducted EMI on the input side of a DC-DC converter or the supply entry of a noise-sensitive load.
Impedance, current, and DCR — the three numbers that decide fit
The 800 Ohm impedance at 100 MHz is the attenuation peak — it tells you how much common-mode noise the choke knocks down at the switching frequency of a typical DC-DC converter. Below 10 MHz the impedance drops off, so this part is tuned for HF noise, not 50/60 Hz mains hum. The 1 A current rating is the continuous DC limit; the 100 mOhm max DCR means the voltage drop across the filter at full current is 100 mV, which matters if the downstream rail has tight regulation. Operating from -25 °C to 85 °C, the choke stays within spec across most indoor and automotive-cabin environments, though the DCR rises with temperature — budget extra margin if the board runs near the upper limit.
Obsolete — sourced through surplus channels
TDK has marked the ACM4532-801-2P-T001 as obsolete. Available through independent surplus and broker inventory. Quantities are lot-specific; pricing and availability are confirmed at RFQ time. No pin-compatible direct replacement is documented, so a BOM substitution requires verifying the footprint and the impedance-vs-frequency curve against the original design.