SLAAET6 August   2025

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1S-Parameter Definition
    1. 1.1 Insertion Loss (S21)
    2. 1.2 Return Loss (S11)
  5. 2High-Speed Signal Design Example Of FPD-Link™ Serializer Body
    1. 2.1 Design Example Overview
    2. 2.2 Key Points in High-Speed FPD-Link Layout Design
  6. 3Factors Impacting Return Loss and Optimization Guidelines
    1. 3.1 Transmission Line Impedance Impact
    2. 3.2 AC Coupling Capacitor Landing Pad Impact And Optimization
      1. 3.2.1 Mitigation Strategy: Anti-Pad Implementation
      2. 3.2.2 Simulation Results With Ansys® HFSS
    3. 3.3 Through-Hole Connector Footprint Impact and Optimization
      1. 3.3.1 Through-Hole Connector Via Anti-Pad Impact
        1. 3.3.1.1 Simulation Results With Ansys® HFSS
      2. 3.3.2 Surrounding Ground Vias Impact
        1. 3.3.2.1 Simulation Results (Surrounding Ground Vias Impact)
      3. 3.3.3 Non-Functional Pad Impact
        1. 3.3.3.1 Simulation Results (Non-Functional Pad Impact)
    4. 3.4 Generic Signal Via Impact and Optimization
      1. 3.4.1 Simulation Results
    5. 3.5 ESD Diode Parasitic Capacitance Impact and Optimization
  7. 4Summary

2.1 Design Example Overview

This section presents a design example based on the FPD-Link serializer. The serializer is used to transmit video data to remote display over a single coax channel, the data rate runs up to 13.5Gbps to support 4K display. All the subsequent analysis and simulations are based on this example. Figure 2-1 depicts the total FPD-Link channel structure on the serializer PCB. Figure 2-2 is the corresponding PCB 3D model of the FPD-Link serializer channel.

Key design specifications:

  • PCB stackup: this example is based on a six-layer stackup with standard FR-4 material (dielectric constant Dk = 4.3, dissipation factor Df = 0.02).
  • Key components: the total FPD-Link serializer channel includes an IC pin, single-ended transmission line, ESD diode, AC coupling capacitor, signal via, and through-hole coax connector.
  • Critical frequency points: FPD-Link line rate runs up to 10.8 and 13.5GHz to support 4K+ resolution display, the frequencies of interest are half of the line rate, that is, 5.4GHz and 6.75GHz.