vSphere supports a USB (host) controller per virtual machine. USB 1.x, 2.x and 3.x supported. One USB host controller of each version 1.x, 2.x, or 3.x can be added at the same time.
A maximum of 20 USB devices can be connected to a virtual machine (Guest operating systems might have lower limits than allowed by vSphere)

vSphere 5 introduced limited support for USB3.0 devices (pass-through from client device to Linux guests only). Previous USB versions are fully supported for Windows and Linux guests and pass-through from client and host to the virtual machines.