Minimise PCB emissions through simulation-based optimisation of termination

Reducing the emissions in order to meet the various regulatory standards is often unnecessarily painful. Due to the complex nature of electromagnetic interactions, locating the exact path that the emissions should take to exit the enclosure is difficult. This paper presents the methods of minimizing the PCB emissions through the simulation-based optimization of terminations. The details of the parallel, series, and diode termination strategies were discussed. Significant reductions in the final EMI emissions are obtained through the reduction of the high frequency content of the common-mode currents and the harmonic-frequency amplitude of international trace currents. These reductions are obtained at no cost since the cost of a resistor in not based on an ohmic value.