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Parameter
Time-domain Reflectometer (TDR) Dip
GEN1
GEN2
Near End Crosstalk (NEXT)
GEN1 IL/NEXT plot
Impedance
Trace Impedance: Diff pair / Single Ended
Reference plane
Trace Length/Skew
Trace loss characteristic:
GEN1
GEN2
•
The following max length is derived based on the trace loss characteristic above. The length constraint must be re-defined if loss characteristic is
changed.
•
The trace loss profile for Gen2 support is based on the dielectric material EM370(5). See the loss plots in the sheet "USB3 LOSS BUDGET"
•
Note that microstrip loss could be similar to stripline due to humidity effect
Breakout Region – Max length
Max Trace Length
GEN1 Host
GEN1 Device
GEN2 Host or Device
Max Intra-Pair Skew (RX/TX_N to RX/TX_P)
Differential pair uncoupled length
Trace Spacing for TX/RX Non-
Interleaving
TX-RX Xtalk is very critical in PCB trace routing. The ideal solution is to route TX and RX on different layers.
If routing on the same layer, strongly recommend not interleaving TX and RX lanes
If have to have interleaving routing in breakout, all the inter-pair spacing should follow the rule of inter-S
spacing)
The breakout trace width is suggested to be the minimum to increase inter-pair spacing
Do not perform serpentine routing for intra-pair skew compensation in the breakout region
Min Inter-SNEXT (between TX/RX)
Breakout
Jetson AGX Xavier Series Product
Requirement
Units
75
Ω
75
≤ −45
dB
GEN2 IL/NEXT plot
85 / 43
Ω
GND
< 0.7
dB/in
< 0.9
11
mm
152 (1014)
mm (ps)
50.8 (234)
127 (850)
0.15 (1)
mm (ps)
6.29 (41.9)
mm (ps)
4.85x
USB, PCIe, and UFS
Notes
@ Tr = 200ps (10%-90%)
@ Tr = 61ps (10%-90%)
DC – 5GHz per each TX-RX NEXT
±15%. Intrinsic Zdf, does not account for
coupling from other trace pairs
@ 2.5GHz
@ 5GHz
Minimum trace width and spacing
Stripline (6.7ps/mm) assumed
Do not perform length matching within
breakout region. Trace length matching
should be done before discontinuities. See
Note 2
(between TX/RX pair
NEXT
This is the recommended dimensions for
meeting the NEXT requirement.
DG-09840-001_v2.5 | 44
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