DM9163
Layout Guide
2 Version:
DM9163-LG-V10
May 5, 2014
1. Placement, Signal and Trace Routing
•
Place the 10/100M magnetic as close as possible to the DM9163 (no more than 20mm) and to the RJ-45
connector.
•
Place the termination resistors 50
Ω
as close as possible to the 10/100M magnetic and the DM9163 RX
±
pins and TX
±
pins. The 50
Ω
resistors and grounding capacitors of TX
±
and RX
±
should be placed near
DM9163 (no more than 10mm).
•
The 25MHz crystal should not be placed near important signal traces, such as RX
±
receive pair and TX
±
transmit pair, band gap resistor, magnetic and board edge.
•
Traces routed from the DM9163 RX
±
pair to the 10/100M magnetic and the RJ45 connector should run
symmetrically, directly, identically, and closely (no more than 2mm). The same rule is applied to traces routed
from the DM9163 TX
±
pair.
Magnetic
RJ-45
RX+
RX-
TX+
TX-
d1
d2
d1
d1 < 2mm
d2 > 3mm; having AGND as a shield is better
d3 > 5mm; having AGND as a shield is better
d1
d1
d2
Do not turn at right angle (90
°
),
turn 45
°
instead
Crystal
d3
better
Magnetic
RJ-45
RX+
RX-
TX+
TX-
d1
d2
It’s worse to turn at right angle (90
°
)
Crystal
d3
Worse
d1
Worse
