The line that need branch also has poor model, in all model, strange model, occasionally model? See this you understood
[introduction] speak of to need minute of line, do high speed design to should not know without the person. The biggest acknowledge is interference rejection ability strong. To drawing circuit board for, the collateral bus line of the root that compare sheet is simple. Be like: PCIE of a big line comparing differs DDR a few pairs the trouble that distribute a line became much.
—— of the line that need branch needs a standard, in all model, strange model, occasionally the model is foolish foolish cent is not clear
Speak of to need minute of line, do high speed design to should not know without the person. The biggest acknowledge is interference rejection ability strong. To drawing circuit board for, the collateral bus line of the root that compare sheet is simple. Be like: PCIE of a big line comparing differs DDR a few pairs the trouble that distribute a line became much.
A few days ago the child of the company asks a skin, what is wrong standard, in all model, strange model, occasionally model? Say foolish foolish cent is not clear. Want in those days, when Pi Pigang is contacted, also be foolish foolish cent is not clear.
We see the idea of the line that need branch first:
Simple for differ minute of on-line namely two lines are going voltage identical, the story that kills loves each other between two phasic and opposite signal. This Zhangqiao becomes warped below board picture, very the explanatory difference of figure distributes a line. A little while go up, go up negatively a little while, but from beginning to end around nod among the move.
The picture comes from a network
In the weaveform that pursues as follows, vp is + , vn is – . Green Vdiff is the poor value of two signal, formation difference distributes signal.
Need a standard, in all model:
Wrong standard appears here, in all model these two concepts: Two Chan Duanxin date combine random together, can resolve difference model and in all model two heft. From below will look on mathematical formula very intuitionistic.
The basis is formulary Vcomm is a constant value, such Vp and Vn can use Vdiff and Vcomm to express. Like unlike a signal uses dc weight + communication heft. Learn this constant value, when it is not constant, with respect to the problem that can produce signal integrality and EMC.
Strange model, occasionally model:
From above in light of, need a standard, in all the model is the relation between two lines. Strange model, occasionally the model is odd root line be opposite respectively the relation of the ground. Be the same as when two lines phasic, it is occasionally model.
From below in this graph, the very clear also distinction that sees them:
Affirmative now somebody can ask, what relation be between them? Have of course, how does otherwise put.
Their maths concerns as follows:
To here, everybody should have a clear knowledge to these 4 concepts.
But, can misunderstand, the characteristic impedance the sum that differs minute of impedance to be equal to odd root line (mistake) . Actually, before leather skin also so think, but leather skin is calculated with impedance software, this relation does not hold water. Because,this is our oversight the coupling between two lines. There should be magnetic field to make the problem that there is a coupling coefficient when the meeting between two lines. Place divides signal to be able to compare them toward difference before the sum of odd root signal wants low. Achieve today’s top headlines formerly: Lie dragon is met IT technology
Following, what see from inside some article is formulary, the definition differs minute of impedance.
The watch below also shows an issue, different space is apart from, below the circumstance of the identical impedance that need branch, the value of other impedance, can see, the value of the impedance that need branch differs at all the characteristic impedance the sum of odd root line.
Last column is characteristic impedance.
Good, above is 4 ideas that I explain to the child, also be the process that ego summary arranges. The hope can share everybody. Help somewhat to everybody. Also can discuss with respect to this problem.
Avoid duty statement: The article is reprint an article, reprint this article purpose to depend on passing more information, the person that copyright puts in original work ‘s charge is all. If involve work copyright issue,article place uses video, picture, written language, contact please small make up undertake handling.