Table of Contents
Advertisement
Parameter
Impedance
Trace impedance (Diff pair)
Reference plane
Trace spacing/Length/Skew
Trace loss characteristic:
Trace spacing (pair-pair)
Stripline
Microstrip: pre 1.4b
Microstrip: 1.4b/2.0
Trace spacing (Main link to DDC)
Stripline
Microstrip
Max total length/delay (1.4b/2.0 - up to 5.94Gbps)
Stripline
Microstrip (5x spacing)
Microstrip (7x spacing)
Max Total Length/Delay (Pre-1.4b)
(up to 165Mhz)
Microstrip
Stripline
Max intra-pair (within pair) skew
Max inter-pair (pair to pair) skew
Max GND transition via distance
Via
Topology
Minimum impedance dip
Recommended via dimension
drill/pad
Antipad
via pitch
GND via
Max # of vias
PTH via
u-via
Max via stub length
Topology
The main route via dimensions should comply with the via structure rules (See via section)
For the connector pin vias, follow the rules for the connector pin vias (See via section)
NVIDIA Jetson TX2 NX
Requirement
Units
<= -40
dB at 6GHz
IL/FEXT plot: See Figure 7-9
100
GND
< 0.8
dB/in. @ 3GHz
< 0.4
dB/in. @ 1.5GHz
3x
dielectric
4x
5x to 7x
3x
dielectric
5x
63.5/2.5 (437)
mm/in (ps)
50.8/2.0 (300)
63.5/2.5 (375)
254/10 (1500)
mm/in (ps)
225/8.5 (1500)
0.15 (1)
mm (ps)
150
1x
Diff pair via pitch
Y-pattern is recommended
keep symmetry
97
Ω@200ps
92
Ω@35ps
200/400
840
880
Place GND via as symmetrically as possible
to data pair vias. Up to four signal vias (2 diff
pairs) can share a single GND return via
4 if all vias are PTH via
Not limited if total channel loss meets IL
spec.
0.4
mm
Notes
TDR plot: See Figure 7-10
±10%. Target is 100Ω. 95Ω for the
Ω
breakout and main route is an
implementation option.
The max length is derived based on
this characteristic. See Note 1.
For Stripline, this is 3x of the thinner
of above and below.
For Stripline, this is 3x of the thinner
of above and below.
Propagation delay: 175ps/in. for
stripline, 150ps/in. for microstrip).
Propagation delay: 175ps/in. for
stripline, 150ps/in. for microstrip).
See notes 1, 2, and 3
ps
See notes 1, 2, and 3
For signals switching reference
layers, add one or two ground
stitching vias. It is recommended they
be symmetrical to signal vias.
Xtalk suppression is the best by Y-
pattern. Also, it can reduce the limit
of pair-pair distance. Need review
(NEXT/FEXT check) if via placement is
not Y-pattern. See Figure 7-11
uM
GND via is used to maintain return
path, while its Xtalk suppression is
limited
long via stub requires review (IL and
resonance dip check)
See Figure 7-8
DG-10141-001_v1.1 | 40
Display
Advertisement
Table of Contents
