Impedance and current — the two numbers that decide fit
TDK ACM2520-102-2P-T002 is a 2-line common-mode filter from the ACM series, rated for 1 kOhm impedance at 100 MHz. That impedance is the suppression you get at the switching fundamental of a typical DC-DC converter or the clock edge of a digital interface — 1 kOhm at 100 MHz knocks down common-mode noise by about 60 dB into a 50-Ohm line, which is enough to keep a 20 VDC power rail clean for sensitive analog or RF stages. The 200 mA current rating and 900 mOhm maximum DCR together set the thermal budget: at full rated current the I²R loss is 36 mW, well within what the 2520 footprint can dissipate without derating.
Package and mounting — 2520 footprint, 4-pad layout
The 0.051" (1.30 mm) seated height keeps it low-profile for tight board stacks. Tape & Reel and Cut Tape packaging options are both available.