900 Ohm common mode choke for power lines
The TDK ACM4520-901-2P-T000 is a two-line common mode choke from the ACM series, designed to suppress conducted EMI on DC power rails up to 50 V. Its 900 Ohm impedance at 100 MHz targets the 30-300 MHz band where switching regulators and digital clocks radiate — a typical fit for the input or output of a buck converter feeding a sensor node or a small motor drive.
Current handling and DC resistance
Rated 2.3 A continuous with a maximum DC resistance of 60 mOhm. At full load the I²R loss is about 0.32 W, which the 4.70 x 4.50 mm horizontal package dissipates into still air up to 85°C ambient without forced cooling. The 50 V DC voltage rating gives headroom on 12 V, 24 V, and 48 V rails — just not 60 V+ bus voltages.
Package and board fit
Surface-mount in a horizontal, 4-pad configuration (package / case: Horizontal, 4 PC Pad). The two-line winding means one component filters both the supply and return conductors, saving board area over two separate ferrite beads.
The ACM series is a power-line filter class, so it sits on the DC input or output of a converter — not on a signal line where a smaller bead would do.