Last Updated: 20060803, mei
M2 - PARTITIONING AND LAYOUT OF MIXED SIGNAL PCB
Presenter:
Henry W. Ott, Henry Ott Consultants
Abstract:
Controlling noise on a mixed-signal PCB can be a difficult problem. This is especially true on boards with multiple ADCs. Some designers suggest splitting the ground plane in order to isolate the digital ground from the analog ground. Although the split-plane approach can be made to work, it has many potential problems.
This presentation clearly describes the principles involved in the layout of a mixed-signal PCB and demonstrates that component placement, partitioning, and proper board topology, combined with routing discipline, are the keys to success in laying out a quiet mixed-signal PCB.
By understanding how and where high-frequency ground currents flow, we are able to develop an approach to controlling noise while, in most cases, still maintaining a single contiguous ground plane.
