Genesys GL3520 - Differential Pair Layout

USB 3.0 Hub Design Guide
© 2015 Genesys Logic, Inc. - All rights reserved. Page 11
GLI Confidential
2.3.7 Differential Pair Layout
The routing of a differential pair must be kept as same length, same width, same layer and fixed space gap,
and also be kept as symmetric as possible. (as shown in Fig. 2.7)
Bad Layout: Non-symmetric
Preferred Layout: symmetric routing
Figure 2.7
When vias are used, they should always be placed in same location and symmetric. (as shown in Fig. 2.8)
Bot layer
differential pair
Via
Top layer
differential pair
Perferred example
Via placement is symmertic and in same location
Bad example
Via placement is not symmertic / in same location
Figure 2.8