EMI FILTER DEVICE

1 . An EMI filter device comprising:

a signal processor configured to output a predetermined signal and output a noise source generated in a circuit; and

a coil device for removing the noise source,

wherein the coil device comprises a common mode coil including a first coil and a second coil on one core,

wherein the first coil and the second coil are electrically connected to each other.

2 . The EMI filter device of claim 1 , wherein the first coil and the second coil are wound by one coil.

3 . The EMI filter device of claim 1 , wherein the coil device further comprises a capacitor X for removing differential mode noise.

4 . The EMI filter device of claim 1 , wherein the first coil is installed on a substrate including a first surface and a second surface that are opposed to each other, and the second coil is installed on a substrate including a third surface and a fourth surface that are opposed to each other,

wherein the first coil is installed to connect the first surface and the second surface, and the second coil is installed to connect the third surface and the fourth surface.

5 . The EMI filter device of claim 4 , wherein the first surface and the second surface are located on an upper portion of the third surface and the fourth surface, and the second surface is electrically connected to the third surface.

6 . The EMI filter device of claim 4 , wherein the substrate is a multilayer printed circuit board.

7 . The EMI filter device of claim 6 , wherein, in a first layer and a fourth layer, the first surface and the second surface are connected through the first coil and the third surface and the fourth surface are connected through the second coil,

wherein, in a second layer and a third layers, the second surface is electrically connected to the third surface.