Pdf analysis and modeling of signal integrity problems. This paper discusses a methodology employed to create a tool that quantifies the effects of signal integrity limitations particularly for highspeed applic. Phase and amplitude preemphasis techniques for lowpower. Emphasis will typically have lower power than equalization. The attenuation of the signal is not uniform across all the frequency ranges. Lecroy extends analysis and simulation offerings with signal integrity studio software package. If you really want to understand the theory, you need to complement this book with deeper books such as brian youngs book digital signal integrity. Analysis of preemphasis techniques for channels with higher. Reducing highfrequency attenuation is not achie ved only by boosting the signal strength because. This is shown in the first section of the above figure. Pre emphasis when the frequency of the signal goes above 1 ghz, you will notice that the signal attenuation becomes significant. Although highspeed data rates correlate with highfrequency signals, it is the signal edge timing that has the most detrimental effect on signal integrity.
Modeling and simulation with interconnects and packages or stephen halls book advanced signal integrity for highspeed digital designs. When the frequency of the signal goes above 1 ghz, you will notice that the signal attenuation becomes significant. Understanding the preemphasis and linear equalization features in stratix iv gx devices november 2010 altera corporation figure 8 shows the eye diagram of a prbs7 pattern after a lossy channel without pre emphasis shown on the left and with certain pre emphasis taps on shown on the right. Preemphasis boosts only the highfrequency signal components. Particular emphasis is placed on rigorous derivation and on multiconductor interconnects. The impact of highspeed deemphasis and multistage passive rc. The pre emphasis technique based on pulsewidth modulation pwm using timing resolution instead of. As the signal above passes through a microstrip line, all of the spectral lines do not propagate at. Lecroy extends analysis and simulation offerings with. Chapters and then cover issues in signaling and signal integrity. The signal flows in the left wire and returns from the right wire.
Understanding the preemphasis and linear equalization. Let us assume that the signal pair consists of a wire and a returning ground pair. Analysis and modeling of signal integrity problems in the serial communication devices. Chapter discusses the role of signal integrity in digital systems. Preemphasis is a way to boost only the signals highfrequency components, while leaving the lowfrequency. The book is organized to move gradually from broad, general topics to specific modeling techniques. Abstracta novel approach to equalization of highspeed serial links combines both. Signal integrity basics by anritsu field application engineers table of contents 1. Signal integrity 101 a brief overview of signal integrity and where it fits in the digital design process. Deemphasis is a wellknown signal conditioning technique that. Equalization is capable of greater boost emphasis benefits.
The magnetic field produced by the signal carried in the left wire is equal and opposite to the magnetic field produced by the right wire. It is likely that only one channel compensation strategy will be needed. The higher frequency components suffer more attenuation as compared to the low frequency signals. The significant difference between the two eyes demonstrates how preemphasis can improve signal integrity through the lossy channel. The use of pre emphasis and equalization can help the signal integrity of a transmission path, provided that you carefully select the parameters. Increasing the vod at the driver improves the signal at the receiver.
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