差分布线方式是如何实现的？
<span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New="New" Roman'; mso-hansi-font-family: 'Times New="New" Roman'; mso-bidi-font-family: 'Times New="New" Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">差分对的布线有两点要注意，一是两条线的长度要尽量一样长，另一是两线的间距</span><span lang="EN-US" style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New="New" Roman'; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">(</span><span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New="New" Roman'; mso-hansi-font-family: 'Times New="New" Roman'; mso-bidi-font-family: 'Times New="New" Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">此间距由差分阻抗决定</span><span lang="EN-US" style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New="New" Roman'; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">)</span><span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New="New" Roman'; mso-hansi-font-family: 'Times New="New" Roman'; mso-bidi-font-family: 'Times New="New" Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">要一直保持不变，也就是要保持平行。平行的方式有两种，一为两条线走在同一走线层</span><span lang="EN-US" style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New="New" Roman'; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">(side-by-side)</span><span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New="New" Roman'; mso-hansi-font-family: 'Times New="New" Roman'; mso-bidi-font-family: 'Times New="New" Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">，一为两条线走在上下相邻两层</span><span lang="EN-US" style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New="New" Roman'; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">(over-under)</span><span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New="New" Roman'; mso-hansi-font-family: 'Times New="New" Roman'; mso-bidi-font-family: 'Times New="New" Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">。一般以前者</span><span lang="EN-US" style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New="New" Roman'; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">side-by-side</span><span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New="New" Roman'; mso-hansi-font-family: 'Times New="New" Roman'; mso-bidi-font-family: 'Times New="New" Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">实现的方式较多。</span>
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