Signal/Power Integrity Analysis of High-Speed Memory Module with Meshed Reference Plane

Abstract

In this paper, the signal integrity and power integrity of mesh patterns are investigated in the Double Data Rate 4 Small Outline Dual In-line Memory Module (DDR4 SODIMM). The mesh patterns are designed to be a square in the power plane and are repeated periodically with a spacing of 1 mm. The sizes of the mesh patterns are considered in terms of the operating speed of the DDR4 SODIMM and its wavelength. The effect of signal integrity on the address line is analyzed as the mesh size increases. The eye-diagram analysis of the address line is also carried out by comparing the aperture factor. As the mesh size increases, the eye-diagram aperture decreases. It is verified that the mesh size of 1 mm 2 or less has little effect on the signal transmission of the address line. The power integrity of the power planes with different mesh patterns is analyzed. The effect of resonance and impedance on the power-ground plane is investigated. In this work, it is demonstrated that the mesh size smaller than 1 mm 2 has the same impedance results as the solid plane. However, as the mesh size exceeds 1 mm 2 , the impedance increases in all frequency ranges.