With　the　widespread　application　of　EMI　filters,　a　method　to　improve　power　density　has　become　a　main　concern　in　switch　mode　power　supplies.　Many　previous　works　have　been　done　for　improving　the　EMI　filtering　performance　of　chokes.　This　article　investigates　an　integrated　choke　structure　that　can　minimize　the　leakage　magnetic　flux,　enlarge　the　DM　inductance,　and　improve　the　DM　noise　suppression　performance.　Compared　to　discrete　EMI　filter　inductors,　the　proposed　stacked　choke　scheme　can　integrate　CM　and　DM　chokes　into　toroidal　cores　by　applying　a　combination　of　different　types　of　toroidal　cores.　The　proposed　inductor　can　exhibit　better　DC　magnetic　saturation　characteristic.　Finite　Element　Method　(FEM)　simulations,　impedance　measurement,　insertion　loss　and　conducted　EMI　noise　spectrums　(150　kHz-30　MHz)　are　used　to　validate　the　accuracy　of　the　theoretical　analysis　and　the　proposed　equivalent　magnetic　reluctance　models.