Comparison Between Corner and Center Supply Pinned Octal Driver Logic Families

The phenomenon of EM radiation from switching currents is not new. But the increase of mandatory requirements, FCC, IEC CISPR, European Norms etc., with respect to both emission and immunity of all digital products makes it necessary for the components customer (equipment manufacturer) to take all possible precautions at the components level. For functional reasons, current practice dictates that high-speed logic ICs should be mounted on multilayer boards with ground and/or supply planes, and if these boards are properly designed, the main source of EM radiation is the ICs themselves, and the main area where radiation can be reduced and immunity increased will be in the IC package and circuit design. This paper discusses the advantages of center-supply-pinned ACL-ICs over corner-pinned devices of various families, and gives the theory together with test-results and the requirements derived from the product standards for both emission and immunity of the devices.