Patent attributes
A printed circuit board has separate first, second and third sections arranged in a predetermined direction. A connector is mounted at the first section. A noise cut filter is mounted at the second section and connected to the connector. An electronic circuit component is mounted at the third section and connected to the noise cut filter. An electrically conductive power source layer is formed within the printed circuit board at a position outside a peripheral section adjacent the second section. The noise cut filter is allowed to operate without receiving any influence of noise from the power source layer. Noise is sufficiently removed at the noise cut filter. Noise is suppressed to the utmost in electric signals in the connector. Radiation of noise is reliably reduced at the connector. Electromagnetic interference can be suppressed.