Nvidia Jetson Orin NX - 9.1 eDP and DP

USB and PCIe
PRELIMINARY INFORMATION
NVIDIA Jetson Orin NX DG-10931-001_v0.1 | 32
7.2.1 PCIe Design Guidelines
The following table provides the PCIe routing guidelines for Gen3 and Gen4.
Table 7-9. PCIe Interface Signal Routing Requirements up to Gen4
Parameter Requirement Units Notes
Specification
Data Rate / UI Period
Gen3
Gen4
8.0 / 125
16.0 / 62.5
Gbps / ps
Topology Point-point
Unidirectional, differential. Driven by
100MHz common reference clock
Termination 43 Ω To
GND
Single Ended for P and N
Impedance
Trace Impedance
differential / Single Ended
85 / 50
Ω
±15%
Reference plane
GND
Fiber-weave effect (Only required for Gen4)
• Use spread-glass (denser weave)
instead of regular-glass (sparse
weave) to minimize intra-pair skew
• Use zig-zag route instead of straight
to minimize skew, this is mandatory
for PCIe gen4 design
Example of zig-zag routing (See Figure
7-11)
Spacing
Trace Spacing (Stripline)
Pair – Pair
To plane and capacitor pad
To unrelated high-speed signals
4x
4x
4x
Dielectric
height
TX and RX should not be routed on the
same layer. If this is required in a design,
they should not be interleaved, and the
spacing between the closest RX and TX
lanes must be 9x Dielectric height
spacing.
Length/Skew
Breakout region (Max delay)
41.9
ps
Minimum width and spacing. 4x or wider
dielectric height spacing is preferred
Gen 4.0 max trace:
Direct to device:
Insertion loss / length (delay)
Routing to 2
nd
Orin Module
Insertion loss / length (delay)
Routing to M.2 (NVMe) connector/card:
Insertion loss / length (delay)
-20.51 / 345 (2208)
-14.74 / 248 (1587)
-11.01 / 185 (1185)
dB / mm (ps)
Direct to device Insertion loss budget is
for PCB routing, connectors, and end
device (See Note 1). EM-370(Z) PCB
material is assumed in the length/delay
calculations:
Gen 4.0: -1.51 dB/in @ 8Ghz
Gen 3.0: -0.86 dB/in @ 4GHz
Length to delay calculations assumes 6.4
ps/mm (average of stripline and
microstrip).
The 2
nd
Orin Module loss assumption is:
Gen 4.0: -8 dB @ 8GHz
Gen 3.0: -6.5 dB @4GHz
The PCIe/M.2 connector/card loss
assumption is:
Gen 3.0 max trace:
Direct to device:
Insertion loss / length (delay)
Routing to 2
nd
Orin Module
Insertion loss / length (delay)
Routing to PCIe/M.2 connector/module:
Insertion loss / length (delay)
-15.8 / 467 (2987)
-10.5 / 310 (1985)
-7.6 / 224 (1437)
dB / mm (ps)