Systems for power over data line applications with low mode conversion are described. For example, an apparatus may include a magnetic core; a first conductive coil wound in a first winding direction around the magnetic core; a second conductive coil wound in a second winding direction around the magnetic core; a first conductive lead connecting a first end of the first conductive coil to a first pin; a second conductive lead connecting a second end of the first conductive coil to a second pin; a third conductive lead connecting a first end of the second conductive coil to a third pin, wherein lengths of the first conductive lead and the third conductive lead are equal; and a fourth conductive lead connecting a second end of the second conductive coil to a fourth pin, wherein lengths of the second conductive lead and the fourth conductive lead are equal.