USB 3.0 - Technology and Signal Extension
Applications for HD Video
What is USB 3.0
USB 3.0 (aka SuperSpeed or SS) is the successor to USB 2.0 and increases the data rate more than 10 fold, from 480 Mbps (USB 2.0) up to 5 Gbps (USB 3.0). USB 3.0 is often designated by color coding the connector inserts blue, rather than the common black and white connector inserts and by the addition of the “SS” added to the normal USB icon.
USB 3.0 brings a number of improvements over USB 2.0 including: 5Gbps transfer speeds, Full Duplex (i.e. simultaneous send and receive), Sync-N-Go technology that minimizes user wait-time and power delivery up to 900mA (900 mA on PC ports only. USB charging-only adapters can exceed this and deliver higher charging currents of 1A, 1.5A, 2A 3A, etc…). This upgrade from 500mA to 900mA explains why your smartphone never seems to charge when plugged into your PC’s old USB 2.0 ports but charges steadily albeit slowly when plugged into your PC’s 3.0 port. Your smartphones original charging adapter may provide between 1A and 2A or on some even 3A.
Physical Changes with USB 3.0
USB 3.0 connectors add an additional 5 pins to the 4 pins of USB 2.0, for a total of 9 pins. The connectors are backwards compatible to a certain extent. The flat and ubiquitous “A” connector that we see on all PCs is fully compatible both ways between USB 2.0 and 3.0. You can plug USB 2 into 3 and USB 3 into 2, as the depth of the USB 3.0 A’s added 5 pins is more recessed inside the connector and poses no physical or electrical conflicts. The other connectors however, “B” (the squarer plug historically found on printers), and “micro-B” (found on most modern Android phones) allow USB 2.0 B and micro plugs to fit into USB 3.0 B and micro jacks respectively. However, due to physical size, USB 3.0 B and micro-B connectors will not fit into USB 2.0 jacks. There is no USB 3.0 analog for the USB 2.0 mini connector (small “D” shaped connector found on older phones and many cameras). Here is a visual comparison of connectors including USB 2.0 A: USB 3.1 and the USB “C” connector are newer evolutions of the USB technology and are not addressed here.