Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [high-speed]

High-speed design deals with designing circuits which are working at high frequencies where side-effects like path inductance gain significant influence.

Further reading:

  • Howard Johnson, Martin Graham: High-Speed Digital Design - A Handbook of Black Magic
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How is 10G Ethernet physically possible?

10 gigabit Ethernet means that 10 billion bits are transmitted every second, but I don't understand how this is physically possible (let alone 100G Ethernet). The fastest CPUs today only run at ~8GHz, but even if transmission doesn't require a CPU,…
HaLailah HaZeh
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Why would you stack a resistor and capacitor on top of each other?

I've inherited an charge amplifier/shaping circuit from my predecessor. When he wanted to make a low-pass filter with current-to-voltage conversion, he had a standard circuit like: simulate this circuit – Schematic created using CircuitLab He…
Seth
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PCIe, diagnosing and improving an eye diagram

I have implemented a design that uses PCIe. It is somewhat different in that the PCIe interface is used as a chip-to-chip communication lane on a single PCB (e.g. no PCIe connector). The root complex device is a Freescale i.MX6 which is PCIe Gen 2…
Funkyeah
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Do chips really need multiple values of decoupling capacitor in the same packages?

A similar question is asked here: "two bypass/decoupling capacitors" rule? But that question was about parallel bypass capacitors without mentioning package size (but the answers mostly assumed paralleling parts with different package sizes), while…
Rocketmagnet
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Why doesn't controlled impedance depend on track length?

High speed design noob here. Resistance increases as wire gets longer, but I found in saturn pcb calculator the impedance depends only on track geometry and distance from plane. Say for DDR3 single ended signals with controlled impedance, does a…
Hemal Chevli
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Terminating shielded/screened twisted pair correctly

Theoretically, I can't see a problem if the twisted pair has an end of cable termination that is: - A single resistor (R) that matches the characteristic impedance of the cable placed across the two ends of the pair or, Two resistors…
Andy aka
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USB differential pair length

I am routing a PCB that uses a USB connection. The differential pair traces are 10 mil distant from each other, and they are about 1mm different in length. Is it going to be a problem? What is the recommended maximum difference in length and the…
mFeinstein
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Lengthening a 5 ns pulse

I have a 5 ns pulse width High coming out of a comparator that is asynchronous. I am attempting to count this pulse. My current microcontroller (dsPIC33FJ) has an asynchronous counter on board, with a min spec of at least 10 ns pulse width High.…
Cameron
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What is ground bounce?

From David's comment to this answer I understand that it's an undesirable effect in high speed designs. Can someone explain in detail?
Federico Russo
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How to select an appropriate capacitor for input voltage stabilization

I have a design where I have some high speed ICs and need to put a capacitor on the input voltage line to stabilize the voltage and protect from spikes or dips. I am operating at 5v and between 300 and 500 mA. My research indicates that I need an…
Dabloons
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2-layer USB 2.0 High-Speed routing

First off: This is for a one-off (or two-off) hobby project, nothing more serious. If this were a commercial design, I would go 4-layer at once (though I wouldn't be designing such a project in the first place). Going 4-layer is acceptable only if…
exscape
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Implementing a very high frame rate (~1Khz) OLED display

I'm interested in developing a very high frame rate OLED display capable of displaying ~1000fps with a resolution of around 1200x800 or so. This obviously has some pretty severe bandwidth requirements, and will likely require the use of an FPGA to…
Clifton
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Why doesn't this DIY high-speed probe reflect signals?

I am reading The Art of Electronics, page 809 and 810, where they show this probe: Figure 12.32. Probing digital signals: […] Simple 20× passive “probe” for 50 Ω ’scope input: 953 Ω series resistor to coax This is a DIY probe made out of an RG-178…
mFeinstein
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More Vdd than Vss Pins

I am currently working on my first microcontroller hardware design; I had a microcontroller class in college, but it focused on the software side of things, and used a pre-made development board (for the Freescale 68HC12). I have a question that I…
Don Joe
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Question about trace length matching patterns for high speed signals

A colleague and I had a discussion and a disagreement about the different ways high speed signals can be length-matched. We were going with an example of a DDR3 layout. All the signals in the picture below are DDR3 data signals, so they are very…
SomethingBetter
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