Intel® MAX® 10 High-Speed LVDS I/O User Guide

ID 683760
Date 10/02/2023
Document Table of Contents

6.1. Guidelines: Improve Signal Quality

To improve signal quality, follow these board design guidelines:

  • Base your board designs on controlled differential impedance. Calculate and compare all parameters such as trace width, trace thickness, and the distance between two differential traces.
  • Maintain equal distance between traces in differential I/O standard pairs as much as possible. Routing the pair of traces close to each other maximizes the common-mode rejection ratio (CMRR).
  • Keep the traces as short as possible to limit signal integrity issues. Longer traces have more inductance and capacitance.
  • Place termination resistors as close to receiver input pins as possible.
  • Use surface mount components.
  • Avoid 90° corners on board traces.
  • Use high-performance connectors.
  • Design backplane and card traces so that trace impedance matches the impedance of the connector and termination.
  • Keep an equal number of vias for both signal traces.
  • Create equal trace lengths to avoid skew between signals. Unequal trace lengths result in misplaced crossing points and decrease system margins as the transmitter-channel-to-channel skew (TCCS) value increases.
  • Limit vias because they cause discontinuities.
  • Keep toggling single-ended I/O signals away from differential signals to avoid possible noise coupling.
  • Do not route single-ended I/O clock signals to layers adjacent to differential signals.
  • Analyze system-level signals.