Imported from GitHub: shyver/Industrial-USB3-Hub-USB5744 · commit ba8dd5b · license MIT

Description

A custom 4-layer, 4-port industrial USB 3.0 (5Gbps) hub based on the Microchip USB5744. Features strict 90Ω impedance control, per-port power distribution, and robust ESD protection."

README

Industrial 4-Port USB 3.0 Hub (High-Speed Design)

📌 Project Overview

This repository contains the hardware design files for an industrial-grade, 4-port USB 3.0 (SuperSpeed 5Gbps) Hub.

Designed around the Microchip USB5744 hub controller, this project demonstrates advanced high-speed digital PCB design. It features a strict 4-layer stackup, precisely calculated 90Ω differential impedance routing, length-matching, robust ESD protection, and independent per-port power management.

It is engineered to reliably convert a single USB-C upstream connection into four high-speed USB-A downstream ports in harsh or demanding environments.

(Insert a screenshot of your routed PCB showing the differential pairs here later!)

✨ Key Hardware Features

• SuperSpeed Data (5 Gbps): Full USB 3.1 Gen 1 compliance utilizing edge-coupled differential microstrip routing.
• Impedance Control: Mathematically calculated 90Ω differential impedance ($Z_{diff}$) tuned specifically for the JLC04161H-3313 manufacturing stackup.
• Industrial Power Distribution: Integrated power load switches providing dedicated, current-limited 5V power to each downstream port to prevent cascading short-circuit failures.
• Heavy-Duty ESD Protection: Ultra-low capacitance (< 0.5pF) TVS diode arrays on all SuperSpeed data lines to absorb transient voltage spikes without distorting multi-gigabit signal integrity.
• Clean Clocking: 25MHz external crystal oscillator with localized ground guarding to minimize EMI/Crosstalk.

📐 High-Speed PCB Specifications

To achieve reliable 5 Gbps data rates, standard 2-layer routing is insufficient. This board utilizes a custom 4-layer stackup to provide immediate, unbroken return paths for high-frequency signals.

• Stackup Architecture:
  • Layer 1 (Top): High-Speed Signals
  • Layer 2 (In1): Solid Ground Plane (Continuous Return Path)
  • Layer 3 (In2): Power Planes (5V, 3.3V, 1.2V)
  • Layer 4 (Bottom): Low-Speed Signals & Support Components
• Impedance Math (USB 3.0 SSTX/SSRX & USB 2.0 D+/D-):
  • Target Differential Impedance: 90 Ω ±10%
  • Substrate Dielectric ($E_r$): 4.05
  • Distance to Ground ($H$): 0.0964 mm
  • Calculated Trace Width ($W$): 0.20 mm
  • Calculated Trace Gap ($S$): 0.18 mm

📂 Repository Structure

• /Hardware - KiCad 8.0 project files (.kicad_sch, .kicad_pcb).
• /Docs - Datasheets for the USB5744, Power Switches, and Ultra-low capacitance TVS diodes.
• /Calculations - Screenshots and data for the impedance and stackup calculations.
• /Fabrication - Gerber files, Drill files, BOM, and CPL files ready for PCBA.

🚀 Getting Started

1. Clone this repository: git clone https://github.com/YourUsername/Industrial-USB3-Hub-USB5744.git
2. Open the .pro or .kicad_pro file in KiCad.
3. Note: Ensure your KiCad DRC rules are configured for the 4-layer constraints detailed above before modifying the layout.

📝 License

This project is open-source and available under the MIT License.