EMC Design Guide for Printed Circuit Boards
Frame 54 of 78
Printed copies are uncontrolled
6. For multi-layer boards the recommended layer stack-up is shown in Figure 56.
Figure 56. Layer Stack-up
7. On boards without a ground plane, i.e. two-sided boards, power and ground traces
should be routed adjacent to or on top of one another on different layers to reduce
loop area (Figure 511).
8. A solid ground 'island' should exist underneath all High Speed Integrated Circuits
(HSICs) on surface layers. Figure 57.
9. Whenever possible, place a ground via next to all IC's ground pins as shown in Figure
57. Frequent use of vias interconnecting grounds on both sides of PCB or on
different layers of the board may help lower RF impedance in the ground structure.
Figure 57. IC Ground
10. All ground planes, belonging to the same net, should be conductively tied together
with low impedance connections at each component's ground pin.
Via to GND
Via to VCC
Component Side - horizontal routing
Bottom side vertical routing
High speed - vertical routing
High speed horizontal routing