Analysis of DRAM EMI dependence on data pattern and power delivery design using a near-field EMI scanner

This paper presents the analysis of DRAM-related EMI dependence on DQ/GIO data patterns and power delivery design. The EMI levels of two types of DDR2 667 memories are tested and the near- and far-field emission levels are measured at 1 GHz frequency (the 3rd harmonic of the clock). Five types of DQ patterns, which have different magnitudes of EMI-related frequency, are forced to transmit repeatedly and the effect on radiated emission are measured. As well, two DRAM chips, which have different power delivery design, are tested to see the effect of power delivery design with the data pattern dependency.