高速PCB 阻抗匹配问题请教

dylink_lin

现在遇到的难题: PCB板上面有十几对差分线,要求阻抗100OHM, 传输速度2Gbps;
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我现在将差分线线宽设置为0.25mm, 间距0.25mm,板层设置为TOP, GND,POWER,BOTTOM, 不知是否正确?要将差分对阻抗控制在100OHM, 差分线线宽, 厚度,四层板的厚度应该如何设置? 请版主及各位高手帮忙!

dylink_lin

用SI8000大概计算一下

mzsuper

基本同意你的经验值！楼主还是给个stackup给大家，大家才好帮你算呀！
/ V3 K6 U' }6 s% j7 ^4 N7 w! H! [板厂不同的core不同的PP介电常数也不一样！阻抗就不一样！
2 R* W+ l" U7 V7 m, v你以100为试算值！然后允许板厂trace wide and space 在+-1mil内调节
就好了

jasonlu

差分对阻抗软件可以用polar SI 80000计算！具体参数要请教板厂做的技术跟材质了

wdckill

具体计算要根据各生产厂家的参数来设计,同样都是100OHM,但线宽与线距要求是不一样的,我们一般根据SI8000来计算

fenqinyao

原帖由 michaelw_wang 于 2008-6-25 06:53 发表
1 U1 O8 ^9 K: ~8 {2 z% `2 _you need to specify the hight between top/gnd, and bottom/power, to do the calculation.
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normally, if the hight is 5mil, trace width is 5mil, gap between two signals in one pair is 8mil, the differe ...

通过计算，阻抗为105

calen

差分对阻抗软件可以用polar SI 80000计算！

frankyon

差分对走多少阻抗软件可以计算出来!
但是到其他信号或者地的距离如何求得??

michaelw_wang

you need to specify the hight between top/gnd, and bottom/power, to do the calculation.
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' }! L, @& p8 W, {: K7 fnormally, if the hight is 5mil, trace width is 5mil, gap between two signals in one pair is 8mil, the differential impedance is 100 Ohm.