Usb2.0 Trace Length Guidelines; Table 23: Usb2.0 Trace Length Guidelines; Figure 21: Topology For Usb2.0 - Advantech SOM-5992 Design Manual

2.7.3 USB2.0 Trace Length Guidelines

Figure 21 : Topology for USB2.0
Table 23 : USB2.0 Trace Length Guidelines
Parameter
Signal Group
Differential Impedance Target
Single End
Spacing between pairs-to-pairs
(inter-pair) (s)
Spacing between differential
pairs and high-speed periodic
signals
Spacing between differential
pairs and low-speed non
periodic signals
LA
LB
Max length of LA+LB
Length matching
Reference Plane
Spacing from edge of plane
Carrier Board Via Usage
Notes:
1.
H is height above reference plane.
Main Route Guidelines
USB[3:0]+, USB[3:0]-
85 Ω ±10%
55Ω ±10%
7H (MS) and 5H (DS)
Min. 50 mils
7H (MS) and 5H (DS)
Please see the SOM-5992 Layout Checklist
Carrier Board Length
16"
Differential pairs (intra-pair): Max.
GND referencing preferred
Min. 40mils
Try to minimize number of vias
７４
±2 mils
Notes
1
1