The world needed another USB 3.1 hub. Nevermind that they can be purchased for the cost of a sugar-laden cup of coffee. I needed this module block for the future and I always like to design these in chunks when I can.
I chose to design this with parts I could get from Digikey / Mouser. Higher end assembly factories tend to require that and I don’t want to get addicted to insanely cheap parts from LCSC. For a just-for-fun board it doesn’t really matter, I guess.
EDA Tool: Altium Designer
Key Features: 6 layers ( overkill ! ) , 10Gbs digital signals, high speed differential signals.
Experiment #0: I’m new to USB 3.1. 10Gbs is fast for me. The rise time is in the picoseconds (according to Google) and that means I need to focus on signal integrity. I’ve read Signal Integrity and Power Simplified book twice. Luckily, I’ve forgotten most of it and need to read it again. SMILIE
Experiment #1: 0201 – How will JLCPCB handle 0201 passives? No clue. Will it cost a fortune? Probably. I doubt if they are really necessary, but they were recommended by the datasheets so I’m just gonna run with it for now. At the 0201 scale, soldermask dam thickness minimums start to get pushed. This can be overcame with a stencil but it relies on someone paying attention. I’m nervous.
Experiment #2: I’ve always wanted to use TI’s WEBENCH-CIRCUIT-DESIGNER. For some reason it always recommends Texas Instrument switching regulators. I smell bias. For certain passives, it also recommended 0201s. I’m all all for keeping loops tight, but is this really necessary on a wimpy power rail? We’ll see. I followed directions this time. I’ll optimize later.
Experiment #3: MPN: TUSB8020BPHP Why buy a complete 4-power USB hub with enclosure when I can buy just the controller chip for that price!! I’ve never used it before. We’ll see!
I’m going with JLCPCB on this one and using their JLC06161H-2116A Stackup.
