Spectral Analysis of the On-Chip Waveforms to Generate Guidelines for EMC-Aware Design

In modem electronic products the increasing demand for greater performance and throughput often dictates the need for higher operating frequencies. The fundamental operating frequencies of microprocessors, consumer electronics, and networking applications in use today have exceed hundreds of megahertz and are rapidly approaching, and in several cases exceeding, the gigahertz range, and with the current and future technology scaling trends will continue to raise. However, with such increment in frequency often comes an increase in electromagnetic interference (EMI). Therefore, EMI and radiated emissions are a major problem for high-speed circuit and package designers, which is likely to become even more severe in the future. However, until recently, IC and package designers did not give much consideration to electromagnetic radiated emission and interference in their designs. The enforcement of strict governmental regulations and international standards in the automotive domain are driving new efforts towards design solutions for electromagnetic compatibility (EMC). In order to avoid costly design re-spins, EMC compliance must be validated before fabrication with the support of EMC-aware CAD tools and design guidelines. In this work, we propose an effective and practical approach to assess the spectral content of on-chip signals, which are one of the most detrimental sources of electromagnetic (EM) emissions, and provide valuable guidelines to focus the design efforts on reducing the high-frequency harmonics.