EMI-Related Common-Mode (CM) Noise Analysis and Prediction of High-Speed Source-Series Terminated (SST) I/O Driver in System-on-Package (SOP)

This brief presents, for the first time, a comprehensive analysis and prediction of electromagnetic interference-related common-mode (CM) noise for a 20-Gb/s source-series terminated I/O driver in a 65-nm CMOS process. The novel methodology is proposed to systematically analyze and predict the CM noise of an output driver from various dependent parameters, including CMOS process corners, input signal, power supply, and passive interconnections. Analysis reveals that the nonlinear active circuit predominantly produces an asymmetric rise and fall time of the output signal and is an intrinsic source responsible for generating the CM noise. For the SST driver, as the result of the push-pull nMOS-pMOS configuration, CM noise level variations are aggravated under process corners. The post-layout simulation results indicate that the critical step in controlling the CM noise is at the source, rather than improving the matching of passive interconnections. The presented methodology can also be applied to other serializer/deserializer I/O drivers.