A Measurement Setup for Radiated EMI of Un-buffered DRAM Modules

Abstract

As clock frequency and switching current of DRAM (dynamic random access memory) modules are ever increasing, electromagnetic interference (EMI) of such modules is gaining a very high degree of importance. Normally EMI measurements of memory modules are performed implementing complete motherboards or PCs. This makes it very difficult to only separate the radiated EMI of the memory module with a single EMI measurement. This is the first attempt to construct a shielded measurement setup for radiated EMI for DRAM PCBs. The measurement setup is fabricated and tested for un-buffered double data rate (DDR) modules and gives excellent results. This is very helpful in EMI and electromagnetic compatibility (EMC) investigation of memory modules. Although the measurement setup is just implemented for memory modules, the approach can be used for other types of PCBs too.