| 摘要 |
PURPOSE:To suppress the production of normal mode noise by a method wherein a ground pattern is uniformly formed over the whole back surface of a printed circuit board to reduce the number of the magnetic fluxes made by the loop formed on the surface. CONSTITUTION:A pattern for constituting the circuit of a DC-DC converter is formed on the surface 1A which is one surface of a printed circuit board 1. A ground pattern 6 is uniformly formed over the almost whole surface of the back surface 1B which is the other surface of the board 1. The pattern 6 is connected to output terminals 3, 4 and have a function to reduce the number of the clossing fluxes due to the loop formed on the surfaces 1A, thereby reducing the production of normal mode noise. |
