Ideal Ground Split Implementation (For Integrated Rj-45 Without Usb) - Intel 82541PI Design Manual

Figure 9. Ideal Ground Split Implementation (for Integrated RJ-45 without USB)
The table below gives some starting values for these capacitors.
C1, C6
C2, C3, C4, C5,
The placement of C1 – C6 may also be different for each PCB design. For example, all capacitors
might not need to be populated). Also, the capacitors may not be needed on both sides of the
magnetic module.
Systems with integrated USB ports on the magnetics module might have difficulty using a chassis
ground configuration due to the need to get DC ground to certain USB pins. One technique is to
fabricate an incomplete ground split (partially open on one end). By connecting the ground planes
around the RJ magnetics module through a slim, high impedance connection, the path of the high
frequency noise can be controlled.
Application Note (AP-468)
82541PI(ER) and 82562GZ(GX) Dual Footprint LOM Design Guide
Board Edge
Capacitor
Stuffing
Options
C1 C2 C3
Capacitors
RJ/Mag.
Chassis
GND
RJ Shield
Capacitor
connected
Stuffing
to Chassis
Options
GND
C4 C5
Digital
GND
Resistive
Terminations
LAN IC
4.7 µ F or 10 µ F
470 pF to 0.1 µ F
C6
Value
35