LPDDR4 High-speed Parallel Bus Signal Integrity Analysis

With the rapid development of LPDDR(Low Power Double Data Rate)high-speed parallel bus technology,the faster operating frequency and the lower supply voltage make the signal integrity problems become primary solving problems in product design.Compared with LPDDR3 technology,LPDDR4 technology uses higher operating frequency,lower operating voltage that make a greater impact on the integrity of the signal.Based on the latest LPDDR4 high-speed parallel bus as background,signal integrity problems of high-speed circuit design were studied by simulation method.First of all,making the basic theory of high-speed circuit design as a beginning,the thesis introduces the theory of transmission line,theory of signal integrity,theory of power integrity and principle of signal simulation analysis.They provide fundamental theory for the factor simulation analysis before placement and routing and the validation simulation analysis after placement and routing about LPDDR4.Based on this basic theory,to model the transmission line and then to generate RLGC model file by field solver.By using this transmission line model,circuit simulation model based on spice simulation program form was built to simulate and analyze the factor effects of LPDDR4 high-speed parallel about DMI,line length,line space,signal frequency,termination impedance matching and different load before placement and routing.To provide a general guidance advice for the follow-up placement and routing of LPDDR4 by the simulation results.Finally,by an example,the thesis uses signal and power supply collaborative simulation technology to validate the correctness of LPDDR4 placement and routing by simulation analysis.It includes extracting data channel model and power distribution network model based on the S parameter form,building signal and power supply collaborative simulation circuit model and analyzing simulation results.Then,to optimize and simulate the placement and routing about LPDDR4 high-speed parallel bus by improving the power distribution network and increasing the ground protection line around signal line.In addition,compared with the ordinary signal simulation method,the thesis manifests the advantage of signal and power supply collaborative simulation technology.This technology can be used to more accurately simulate the power noise effect on transmission signal under the actual working state of product,and greatly improve the accuracy of the simulation analysis about high-speed circuit design.So it has a very important significance for the high-speed circuit product design.