Thursday, November 5, 2015

Google Engineer Reviews USB-C Cables That Don’t Work

Benson Leung (via Hacker News, Slashdot):

I bought the CableCreation Micro-B receptacle to Type-C plug for testing with Pixel and Nexus devices. I found that this adapter does not correctly charge the Chromebook Pixel and other Type-C devices. My analysis shows that this cable, although will charge and provide data through to the devices, does not correctly follow the USB Type C specification for power delivery identification. The CableCreation adapter advertises itself as 3A capable, but that is not appropriate because this is a legacy host port adapter.


In other words, since you are creating a USB Type-C plug to a USB 2.0 Type-B receptacle assembly, you must use a resistor of value 56kΩ. According to our testing, your cable uses a 10kΩ pull-up, which is not legal when the other end of the cable or adapter is a legacy Type-A or Type-B connector or receptacle.

By using this cable, your phone, tablet, or laptop computer may attempt to draw 3A, which may be more than the micro-b to A cable you attach to this adapter may be able to handle. This may cause damage to whatever cable, hub, pc, or charger you plug into this.

Amazon reviews have their problems, but for many types of products they’re the best available source of information.

Update (2016-03-30): Katie Collins (Hacker News):

The online retailing giant on Wednesday tightened regulations for selling USB Type-C cables. It added faulty USB-C cables to a list of banned items that also includes pirated DVDs and portable lasers. Those selling them risk Amazon shutting down their account and destroying any of their products stocked in Amazon fulfillment centers.

Comments RSS · Twitter

Leave a Comment