What Are the Basic Guidelines for Layout Design of Mixed-Signal PCBs?

A mixed-signal PCB design requires basic understanding of analog and digital circuitry to minimize, if not prevent, signal interference. Modern systems consist of components that are operational with both digital and analog domains, and these must be carefully designed to ensure signal integrity all throughout the system.

PCB layout as an important part of the mixed-signal development process can be intimidating and component placement is just the beginning. There are also other factors that must be considered including board layers and how to properly manage these to minimize interferences caused by parasitic capacitors that can be unintentionally created between the interplane layers of the PCB.

Grounding is also an integral process in the PCB layout design of a mixedsignal system. While grounding is a frequently debated topic in the industry, constructing a standardized approach may not always be the simplest task for any engineer. For instance, a single issue of quality grounding can affect the entire layout of a high performance mixed-signal PCB design. And for this reason, this area should not be overlooked.