A Low EMI characteristic of LPDDR5 SDRAM with Edge-placed PADs and Short Re-Distribution Lines

For mobile DRAM, low EMI (Electro-Magnetic Interference) chip architecture is highly required. So, mobile DRAM's EMI characteristic using center-placed pads and edge-placed pads has been investigated. Our near-field scan measurement results show that the peak H-field magnitude of LPDDR5 using edge-placed pads is lower by 11.5 dB than that of the other one using center-placed pads. Furthermore, when comparing our measurement results to our simulation results showing that the power plane resonance of PoP (Package-on-Package) affects low frequency EMI radiation significantly, we have also noticed reasonable agreement on the peak H-field magnitude trend.