Amazon.com: 4-Port Raspberry Pi USB HUB HAT for Raspberry Pi 4B/3B+/3B/2B/B+/A+/Zero/Zero W, 4 USB Ports Compatible with USB2.0/1.1 Onboard USB to UART Onboard Multi Indicators : Electronics
Design and Build your own High Power USB Hub Port Extender
Signal Integrity Analysis in PCB Design - Advanced Designs Inc.
Design and Build your own High Power USB Hub Port Extender
Master USB 2.0 Hub power management - EDN
Design and Build your own High Power USB Hub Port Extender
7-Port USB Hub IC - EEWeb
Hacker friendly USB hub - Hackster.io
Guidelines on System Design Using Cypress' USB 2.0 Hub (HX2VL)
Reference Designs
Design and Build your own High Power USB Hub Port Extender
2-Port USB 3.0 Hub Reference Design
CY4603: 4-Port USB 3.0 Hub
Design and Build your own High Power USB Hub Port Extender