2 layers65 × 33.4 mm
BL R8812AF1 2x mount
OpenIPC/hardware
A collection of hardware developments by the OpenIPC team
28 parts33MIT
2 layers80 × 35 mm
Usb hub
thatoddmailbox/usb-hub6A four-port USB 2.0 hub based around the CoreChips SL2.1A IC.
- Size
- 80 × 35 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 22
- Nets
- 20
- Pads
- 81
- Tracks, vias
- 163, 5
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 5 (file 20171130)
- Created
- 12 Feb 2021
- Updated
- 21 Jun 2026
Overview
Usb hub is an open-source printed circuit board by thatoddmailbox, from the thatoddmailbox/usb-hub repository on GitHub. It is a 2-layer board of 80 × 35 mm with 22 parts on 20 nets, routed with 163 tracks and 5 vias.
It is built around the SL2.1A. Its parts include 9 capacitors, 6 connectors, 1 IC and 1 crystal. It belongs with the interfaces and adapters boards of this library.
Main components
1README
README.mdusb-hub
A four-port USB 2.0 hub based around the CoreChips SL2.1A IC.
You can choose whether it's bus powered or externally powered with JP1. Soldering JP1 closed selects bus power, while leaving JP1 open means devices are powered with external power, which can be provided through J2.
Note that an external 12 MHz crystal is provided for the SL2.1A. The datasheet claims that the chip also has an internal 12 MHz oscillator that you can use by connecting XIN (pin 16 of the SL2.1) to ground. It's recommended to use the external one, though, as it's more stable. (see the red Chinese text on page 5 of the datasheet)
The port closest to the upstream mini-USB port is port number 1, and the remaining ports are numbered 2 through 4.
Assembly
This board is fairly easy to assemble with a soldering iron, flux, and solder wick. The main thing to watch out for is that the two sets of electrolytic capacitors, near the output ports, have opposite polarities. The silkscreen has the positive side labeled, so you should make sure the negative side of the capacitor (with the black stripe) is opposite of the positive side (as labeled by a plus on the board).
Useful links
Parts
22| Qty | Value | Footprint | References |
|---|---|---|---|
| 4 | 100uF | Capacitors_SMD:CP_Elec_6.3x5.3 | C6, C7, C8, C9 |
| 4 | USB_A | Connectors:USB_A | J3, J4, J5, J6 |
| 3 | 10uF | Capacitors_SMD:C_0603_HandSoldering | C2, C3, C4 |
| 2 | 12pF | Capacitors_SMD:C_0603_HandSoldering | C1, C5 |
| 1 | 12MHz | Crystals:Crystal_SMD_3225-4pin_3.2x2.5mm_HandSoldering | Y1 |
| 1 | Conn_01x02 | Pin_Headers:Pin_Header_Straight_1x02_Pitch2.54mm | J2 |
| 1 | SL2.1A | Housings_SOIC:SOIC-16_3.9x9.9mm_Pitch1.27mm | U1 |
| 1 | SolderJumper_2_Bridged | Jumper:SolderJumper-2_P1.3mm_Open_TrianglePad1.0x1.5mm | JP1 |
| 1 | USB_B_Mini | Connectors:USB_Mini-B | J1 |
The 18 most common of 22 parts.
Questions
How big is the Usb hub PCB?
It measures 80 × 35 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Usb hub use?
22 parts, built around the SL2.1A. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Usb hub KiCad files?
From the thatoddmailbox/usb-hub repository on GitHub, at the commit this page was made from: the board is usb-hub.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the Usb hub design in my own project?
Its repository states no licence, so its author keeps all rights: ask thatoddmailbox before reusing the design.
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