USB and PCIe
NVIDIA Jetson Xavier NX DG-09693-001_v1.7 | 21
6.1.1 USB 2.0 Design Guidelines
These requirements apply to the USB 2.0 controller PHY interfaces: USB[2:0]_D_N/P
Table 6-4. USB 2.0 Interface Signal Routing Requirements
Max frequency (high speed): Bit Rate/UI
period/Frequency
480/2.083/240 Mbps/ns/MH
z
Max loading: High Speed / Full Speed / Low Speed 10 / 150 / 600 pF
Reference plane GND
Trace impedance: Diff pair / SE) 90 / 50 Ω ±15%
Via proximity (signal to reference) < 3.8 (24) mm (ps) See Note 1
Max trace length/delay 150 (960) mm (ps)
Max intra-pair skew between
and
7.5 ps
Notes:
1. Up to four signal vias can share a single GND return via.
2. Adjustments to the USB drive strength, slew rate, termination value settings should not be necessary, but if any are made, they
MUST be done as an offset to default values instead of overwriting those values.
6.1.2 USB 3.2 Design Guidelines
The following requirements apply to the USB 3.2 Port #2 PHY interface: USBSS_TX_N/P,
USBSS_RX_N/P.
Table 6-5. USB 3.1 Interface Signal Routing Requirements
GEN1
5.0 / 200
Gbps / ps
Device mode supports GEN1 speed
only.
On-die termination at TX & RX
Insertion Loss (IL - Min)
Host
GEN1 (Type C)
GEN1 (Type A)
GEN2
Device
GEN1 (Micro AB)
Resonance Dip Frequency
-2
-7
-5.4
-1[*]
> 8
dB @ 2.5GHz
dB @ 2.5GHz
dB @ 5GHz
dB @ 2.5GHz
GHz
• in Gen2 the loss budget is the same
for all types of connector
• dual role mode: host and device have
the same loss budget
[*] the consideration of Gen1 fixture
loss
The resonance dip could be caused by a
via stub for layer transition or trace
Time-domain Reflectometer (TDR) Dip
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