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With increasing speeds of compression and digital signal ("clock") of electronic products, there is a growing concern with the service standards of EMI / EMC so that such products will be successful in certification testing of regulators such as the FCC (Federal Communications Commission) and Anatel (National Telecommunications Agency). To this must have emission characteristics of electromagnetic interference and susceptibility to the appropriate type of equipment to which products belong, as in a printed circuit board (PCB). In equipment design, one important issue is compliance with relevant EMC standards. Effects such as crosstalk, reflections on transmission lines, impulse noise as the simultaneous transition of levels, electrostatic discharge, current spike and radiation or electromagnetic radiation should be considered when using high-speed integrated circuits. These effects combined with the nonlinear characteristics of passive components can cause an erroneous operation at the component level, subsystem and system. Crosstalk is one of the four families of signal-integrity problems. In the simplest terms, crosstalk is unwanted coupling of voltages and currents between neighboring conductors. On a PCB, the conductors are usually traces, although crosstalk can also occur in connectors, cables, and component packages. In the classic scenario, when a signal is intentionally driven on one conductor, an unwanted signal also appears on a neighboring conductor –even though there is no conductive connection between the driven conductor and its neighbor. The noise margin is typically about 15% of the total single-voltage swing, but varies among device families. Of this, about 1/3 or 5% of the signal swing, is typically allocated to crosstalk. Unfortunately, the magnitude of the noise generated in typical traces on board can often be larger than 5%. This is why it is important to be able to predict the magnitude of crosstalk, indentify the origin of excessive noise, and actively work to minimize the crosstalk in the design of packages, connectors, and board-level interconnects. Understanding the origin of the problem and how to design interconnects with reduced crosstalk is increasingly important as rise time decreases. It is important during the development phase of a project to have tools or techniques that can assist with possible problems that may appear only when the equipment is in the field. The costs of re-design and new manufacturing processes can be very high. Therefore, the use of computerized simulation tools is extremely important.