DM9601E ETC1 [List of Unclassifed Manufacturers], DM9601E Datasheet - Page 48

• Manufacturer Part Number: DM9601E
• Description: USB Ethernet MAC Controller with Intergrated 10/100 PHY
• Manufacturer: ETC1 [List of Unclassifed Manufacturers]

14. Application Notes
14.1 Network Interface Signal Routing
Place the transformer as close as possible to the RJ-45
connector. Place all the 50Ω resistors as close as
possible to the DM9601 RX± and TX± pins. Traces routed
from RX± and TX± to the transformer should run in close
pairs directly to the transformer. The designer should be
careful not to place the transmit pair across the receive pair.
As always, vias should be avoided as much as possible.
The network interface should be void of any signal other
than the TX± and RX± pairs between the RJ-45 to the
transformer and the transformer to the DM9601. There
should be no power or ground planes in the area under the
14.2 10Base-T/100Base-TX Application
48
DM9601
BGGND
BGRES
RX+
TX+
RX-
TX-
50Ω
33
34
26
29
30
25
1%
50Ω
50Ω
1%
1%
50Ω
1%
3.3V AVCC
6.8KΩ, 1%
AGND
3.3V AVCC
AGND
AGND
0.1µF
0.1µF
0.1µF
0.1µF
AGND
USB to Ethernet MAC Controller with Integrated 10/100 PHY
Figure 14-1
Transformer
1:1
1:1
network side of the transformer to include the area under the
RJ-45 connector. (Refer to Figure 4 and 5.) Keep chassis
ground away from all active signals. The RJ-45 connector
and any unused pin should be tied to chassis ground
through a resistor divider network and a 2KV bypass
capacitor.
The Band Gap resistor should be placed as physically close
to pins 25 and 26 as possible. (Refer to Figure 1 and 2.)
The designer should not run any high-speed signal near the
Band Gap resistor placement.
75Ω
1%
75Ω
1%
75Ω
1%
Chasis GND
0.1µF/2KV
75Ω
1%
1
2
4
5
7
3
6
8
Version: DM9601-DS-F01
DM9601
RJ45
June 22, 2002
Final