2.10 Designing for High-Speed Peripherals

The PIC32C Family of devices have peripherals that operate at frequencies much higher than typical for an embedded environment. The following list shows the peripherals that produce high-speed signals on their external pins:

Due to these high-speed peripheral signals, it is important to consider several factors when designing a product that uses these peripherals, as well as the PCB on which these components will be placed. Adhering to these recommendations will help achieve the following goals:

• Minimize the effects of electromagnetic interference for the proper operation of the product
• Run all PCB high-speed signals first on component side of PCB
• Ensure signals arrive at their intended destination at the same time by matching critical trace lengths on the PCB
• Minimize crosstalk. Insure continuous ground under all high-speed signals.
• Maintain signal integrity by the use of termination resistors in the 30-50 Ω range
• Reduce system noise by using bulk and high frequency decoupling caps and inductors on power rails
• Minimize ground bounce and power sag. Use a dedicated ground plane if possible or at a minimum a star ground configuration. Do not daisy chain ground and power traces to components.