Determine proper placement of bypass capacitors - before or after the data line filter. If located between the filter and I/O connector, select capacitor with minimum 1500V rating to prevent damage during an ESD event.
Make provisions in the artwork for inclusion of bypass capacitors in the I/O circuit. Use these capacitors only if required for compliance or functional concerns; prepare for the future.
Partition audio interfaces into three areas: digital, analog, and audio. Make the digital-to-analog connection through a bridge located directly under the audio controller or as close to it as possible. Route all traces between digital and analog through this bridge, including analog power. Isolate the analog section from the audio section from the audio section by a second moat and additional data line filters. Do not connect audio ground to chassis or analog ground. Do not connect signal return on unshielded audio cables to analog or chassis ground.
For circuits that carry high levels of ac or dc voltage (> 42.2 V), maximize creepage and clearance distances to prevent an electrical hazard due to an abnormal fault condition that may occur. This is a requirement for product safety.
When designing interconnects keep in mind the following (7.4):
· Keep all discontinuities as short as possible.
· Use as many ground connections as possible within the allocated space or pinout.
· Establish a common ground within the connector.
· Use low-dielectric-constant board materials.
· Maintain the ground path length as close as possible to the path between both signal and ground.
Schematic design of PCB projects 
