Power Integrity

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What is Enough? VDDQ Package Power Integrity Analysis With a DDR4 PHY

As voltage margins for power rails continue to decrease, end-to-end power integrity modeling is already difficult without having to be concerned if all of your simulation models are correct. System designers typically assume that all of the vendor models are correct. So, what does an engineer do if one of the ASIC die models needed for a power integrity simulation is incorrect? 

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VRM Modeling and Stability Analysis for the Power Integrity Engineer

DesignCon 2023 Paper

This paper addresses the challenge of how to simulate the power integrity ecosystem and include the feedback loop and switching noise of a switch mode power supply (SMPS) without waiting days for the simulation results. The solution presented here uses control loop theory state space equations to create a behavioral model of an SMPS that allows for fast simulation.

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Contradicting the Common Belief: Decoupling Capacitors - Is More Always Better?

In the process of circuit design, electrical engineers must carefully position capacitors to decouple the power supply pins of integrated circuits (ICs). Yet, relying solely on a single capacitor for this purpose may potentially decrease the performance of the Power Delivery Network (PDN). Therefore, there exists a need for an elegant and systematic methodology in designing the PDN while utilizing a single capacitor. Within this paper, we analyze the single-capacitor scenario within the context of the PDN and introduce a systematic approach for its design. This approach not only suggests clear guidelines for when favoring a single capacitor over multiple capacitors is appropriate but also showcases that when these guidelines are exceeded, this method can be implemented recursively to achieve an optimal PDN solution.

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Noise in Traffic: Signal Emulation for Automotive Apps

DesignCon 2023 Best Paper Award Winner

Automotive applications present new challenges to high-speed serial technology. Asymmetric, multi-gigabit signaling between sensors, processors, and displays in the unique noise environments of both electric and internal combustion engine vehicles create new problems for signal and power integrity engineers. This paper introduces the signal impairments required for receiver testing in the emerging automotive standards like ASA, MIPI's A-PHY, Automotive Ethernet, and more. Standards specify different sources of noise in different ways, some in the form of time evolutions, others as spectra. This paper focuses on techniques for generating and calibrating each noise source while describing advanced de-embedding techniques and addressing test equipment limitations.

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