October 1, 2008 -- The layout of an efficient mixed-signal design can be both time consuming and challenging. However, diligently working on this type of layout can result in a system with less crosstalk, more noise immunity and better EMI performance. The PCB industry continues gearing toward higher speeds, miniaturized components and denser circuits, and consequently, the coexistence of digital and analog technologies in close proximity has become unavoidable. Add to this an element of RF circuitry, and the designer’s job has just become a bit more difficult.

The layout of a mixed-signal PCB poses many challenges to the OEM design engineer and the PCB designer. It is incumbent on both parties to keep in close coordination throughout the project because the more information that can be provided to the PCB designer, the better. It’s also in the best interest of the PCB designer to be aware of and educated on the different types of circuitry that will be present on the board layout. In other words, he or she should be able to identify the digital, analog and RF circuitry before the start of the layout.

By Syed W. Ali. (Ali is a certified interconnect designer and layout engineer at Nexlogic Technologies, Inc.)