Differential signal routing line distributing system and differential signal routing line distributing method

Abstract

A layout method for the creation of a differential pair for the transmission of signals generates a differential pair between a differential signal sender and a differential signal receiver in a layout of a PCB. Differential signals are transmitted via two wires. A plurality of vertical lines are created on the differential pair. Junctions of the vertical lines and the two wires are defined as pairs of points. A first length between one terminal of the differential signal sender and one point of each pair of points and a second length between the other terminal of the differential signal sender and the other point of each pair of points are calculated. If any difference between the first length and the second length does not fall within an allowable range, the lengths of the two wires are adjusted.

Description

technical field [0001] The present invention relates to a wiring system and method, in particular to a differential signal routing system and method. Background technique [0002] In high-speed printed circuit board (printed circuit board, PCB) design, engineers have taken various measures to solve signal integrity problems, and using differential lines to transmit high-speed digital signals is one of them. Differential lines in a PCB are coupled striplines or coupled microstrip lines, usually routed in parallel with fixed line width and line spacing. In theory, it is required that the signal is transmitted in an odd-mode transmission mode, that is, the phase difference of the positive and negative signals is 180 degrees. When the differential signal propagates in the non-ideal loop, the differential signal transmitted by the differential signal line can be coupled to the greatest extent, eliminating the cluttered signal and reducing the damage of the non-ideal loop to the ...

AI Technical Summary

Problems solved by technology

However, in the PCB layout design, there are always many complicated factors, which lead to the fact that in the actual differential line layout design, only attention is paid to whether the total length of the two transmission lines that make up the differential line is equal, and the following reasons are ignored. Unequal length: 1. The wire length of the chip package part is inconsistent; 2. After the differential line leads out of the pin, in the lead-out area (breakout area) usually due to the dense wiring space and pins, there must be a section of non-parallel running of the differential line. 3. The differential line is in the parallel part, every time it is bent and bypasses passive parts, via holes, screw holes, etc., it will cause local unequal lengths

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