Analysis of SI Problems in PCB Design

writer: G January 26, 2018

If the ICX Tau performance can be improved like the Quantum-SI, will enhance the popularity and get more customers. Because Mentor has PCB design frontend and back end, ICX + Tau advantage can not be replaced by other tools.

Timing issues are of the utmost importance. At present, PCB designers basically use off-the-shelf solutions from core chip manufacturers. Therefore, a major part of the PCB design work is to ensure that the PCB can meet the chip timing requirements. At present, the basic domestic users do not grasp the timing issues. A small number of SQ users will use the Excel table to prepare timing requirements, later measured from the SQ parameters manually fill in the Excel table to calculate whether the final PCB design meets the timing requirements. However, these problems have always been more difficult, both the PCB designer and PCB layout PCB designers are difficult to understand the timing from the chip data sheet. The timing problem is mainly parallel interface problems.

Common SI problems, namely solving driving problems, terminating resistance or series damping resistance numerical calculation, PCB laminated structure and characteristic impedance calculation, trace topology analysis. For common SI problems, Hyperlynx, SQ and ICX can be solved very well. Domestic users have basically mastered how to deal with and analyze common SI problems. As a tool, SQ, Hyperlynx, or ICX can be a good solution. Performance, SQ is that it is itself a PCB layout tools, so its suitable for the actual PCB layout performance is better, that is, the field debugging performance is better. However, SQ does not have the ability to analyze timing, only a simple limited timing measurement function.

The advantages of Hyperlynx are easy to use, but neither timing analysis nor timing measurement. In contrast, Hyperlynx is more EMC predictive, which is a Hyperlynx advantage. ICX's weaknesses in the GUI and complexity of setup scare away most customers. The current common SI problems, mainly PCB layout PCB designer in progress. Schematic PCB designers are basically not doing this work, the main reason is the use of tools are not familiar with and know less about SI.

The issue of microwave transmission, commonly referred to as GHz SI. PCB designs need to address the issues that often arise only in the microwave field due to the small size of traces, vias and materials on the transmission link. The problem of transmission in the microwave section is caused by the serial interface, and it plays an important role in communication. It mainly solves the problem of multi-board, namely, the problem of transmission on the core chip link of the card, namely the connector, the backplane, the connector and the card core chip link. However, the serial link has no timing problem. Only the transmission problem needs to be solved. The inter-symbol interference caused by the change of the signal amplitude and 01 bit stream due to the arrival of the frequency in the microwave band needs to be solved. This part of the problem must be combined using frequency and time domain tools. The current mainstream SQ, Hyperlynx and ICX to deal with these issues is not very effective. Hyperlynx and ICX processing S parameters are done using Eldo, but due to the lack of algorithms in the MGH analysis of long bit streams, the time required is impractical.

  • PCB
  • SMT
  • Stencil






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