Bests & Worsts Reviews from Amazon

Benson here again, reviewing legacy USB Type-C adapter on Amazon. Today I am reviewing Lemeng's "USB 3.0 (Type-A) Male to USB3.1 (Type-C)Female Gold Plated Connector Converter Adapter" This adapter does NOT comply with the USB Type-C specification version 1.2. The documentation can be found at usb.org under developers/usbtypec. The Lemeng adapter violates Section 2.2 of the specification which states the following : "USB Type-C receptacle to USB legacy adapters are explicitly not defined or allowed. Such adapters would allow many invalid and potentially unsafe cable connections to be constructed by users." This is because if you combine this adapter with a USB Type-A to Type-C cable, you may create a dangerous condition where two power supplies may be connected together opposing each other using the combined cable. Furthermore, this adapter violates Section 2.3.1 : "Power is not applied to the USB Type-C host or hub receptacle (VBUS or VCONN) until the DFP detects the presence of an attached device (UFP) port." In my testing, even when no UFP device is attached, this receptacle port's VBUS line is powered on at 5V. It should only be at 5V when a UFP device is present. This adapter and port violates Section 4.5.1.2.1 - Please see figure 4-5. A correct DFP receptacle must use two identical but distinct Rp resistors. According to my testing, the Lemeng adapter's Type-C receptacle has a single 56kΩ resistor on just one of the two CC pins in the receptacle. This means that the Chromebook Pixel 2015 does not detect a charger device at all when the cable is in half of the possible plug orientations, as it depends on the presence of Rp to start charging. Finally, this adapter also claims to support USB 3.1 SuperSpeed, but because it is only a passive adapter, there is no way to support both orientations of a potential USB device. Indeed, when I tried it, it would only enumerate a USB-C thumbdrive in SuperSpeed mode in one plug orientation. Due to the nature of Type-C, building a proper version of such an adapter requires active electronics, specifically a mux that connects the correct SuperSpeed wires depending on the orientation of the plug. This adapter has no such electronics, being a cheap passive adapter. Long story short : This adapter is a type forbidden by the USB Type-C specification, and should NOT exist. It gets my lowest rating of 1-star because there is no simple thing that the manufacturer can do to make this adapter correct. As a consumer, DO NOT buy this cable to convert your USB-A chargers or USB-A hub or host ports