An Open Source 4-Port High Power USB Hub
A well documented project, and its admirable getting actual open source hardware certification, but I think the design isn&#x27;t really suitable.<p>All those separate switching regulators look a nightmare for electromagnetic interference to me, the inductors are unshielded and there is no solid ground plane on the PCB. I would be surprised if USB HS (480mbps) works reliably with this layout. Also, there is no consideration given for ESD protection.<p>A better design would be to have a single more modern high current regulator&#x2F;module (the LM2596 [1] used dates from 1999) and use protected high side load switches to supply the ports.  These kind of high current supplies are a bit tricky (external MOSFETs etc), so a module might be a good shout, example [2], which might even end up cheaper than having 4 discrete regulators and passives.<p>Protected load switches detect overcurrent and turn off the output, sometimes with auto-retry. Its getting harder to find them in packages with legs, but the AP22815[3] looks suitable in a TSOT package that shouldn&#x27;t be any harder to solder than the USB hub IC.<p>Protected load switches could also allow removal of the microcontroller, as they have a simple high&#x2F;low enable pin and fault LED, that could connect to a  simple slide switch and red&#x2F;green LED per channel. They also offer nice features like discharging the output capacitors, and reverse current flow protection.<p>As for the suitability&#x2F;usefulness of a 3A USB hub, if you try and pull 3A through a USB connector, it will get quite warm, especially if you have a micro USB connector on the other end.<p>[1] <a href="http:&#x2F;&#x2F;www.ti.com&#x2F;lit&#x2F;ds&#x2F;symlink&#x2F;lm2596.pdf" rel="nofollow">http:&#x2F;&#x2F;www.ti.com&#x2F;lit&#x2F;ds&#x2F;symlink&#x2F;lm2596.pdf</a>
[2] <a href="https:&#x2F;&#x2F;www.digikey.co.uk&#x2F;product-detail&#x2F;en&#x2F;bel-power-solutions&#x2F;SLDN-12D1ALG&#x2F;179-3029-ND&#x2F;8028727" rel="nofollow">https:&#x2F;&#x2F;www.digikey.co.uk&#x2F;product-detail&#x2F;en&#x2F;bel-power-soluti...</a>
[3] <a href="https:&#x2F;&#x2F;www.digikey.co.uk&#x2F;product-detail&#x2F;en&#x2F;diodes-incorporated&#x2F;AP22815AWT-7&#x2F;AP22815AWT-7DICT-ND&#x2F;9562756" rel="nofollow">https:&#x2F;&#x2F;www.digikey.co.uk&#x2F;product-detail&#x2F;en&#x2F;diodes-incorpora...</a>