Application independent evaluation of electromagnetic emissions for integrated circuits by the measurement of conducted signals

This paper gives measurement methods to evaluate the electromagnetic emission (EME) of integrated circuits (IC). The effect of disturbances of any ICs depend on design and layout of the application the specific integrated circuit is built in. To evaluate the EME behavior independent from the final application the proposed methods apply conducted signals, the RF-voltage at any pin and the so called sum current in the mass system of the IC. For the measurement the IC to be evaluated is built up in a very simplified circuitry on a PCB with a standardized layout. Using the proposed qualification scheme for the measured signals it is possible to give EME parameters for standard ICs in the data book or in application notes. On the other hand the user can evaluate the necessary limits for its specific application and give them to its supplier as a specification. On this base the supplier is able to perform investigations and to fulfil the specification without the knowledge of the final application. In the paper the principles of the measurement of the RF-voltage and of the RF-current are described. Examples show for a microprocessor circuit and standard logic circuits that it is possible to evaluate very clearly the influence of different designs of ICs, e.g. for EMI-improvement