DM9161B
Layout Guide
6 Version:
DM9161B-LG-V10
August 9, 2007
3. Ground Plane Layout
•
Place a single ground plane approach to minimize EMI. Ground plane partitioning can cause increased EMI
emissions that could make the network interface card (NIC) not comply with specific FCC part 15 and CE
regulations.
•
Ground plane need separate analog ground domain and digital ground domain, the analog ground domain
and digital ground domain connected line is far away the AGND pins of DM9161B (see Figure 4).
•
All AGND pins (pin 5, 6, 46) could not directly short each other (see Figure 3-3). It must be directly connected
to analog ground domain (see Figure 3-2).
•
Analog ground domain area is as large as possible
Figure 3-1
Analog ground domain
Digital ground domain
AGND
AGND
AGND
Good
Analog ground domain
Digital ground domain
AGND
AGND
AGND
Worse! AGND direct short
Figure 3-2 Figure 3-3