Although the USB Type-C ® specification was released almost simultaneously with the USB 3.1 specification, the two specifications differ from each other. Type-C introduces new cables and some improved USB features. USB 3.1 (aka 3.1 Gen 2) offers transfer speeds of 10 Gbps.
USB Type-C is compatible with USB 2.0, USB 3.0 and USB 3.1 devices. Type-C offers a new naming convention for certain USB elements.
Type-c Specifies the naming convention
In the USB Type-C specification, the familiar host and device names have been replaced by Downstream Facing Port (DFP) and Upstream Facing Port (UFP). Type C provides the ability to change the function of elements.
Type-C New Features
Reversible cable
USB Type-C defines a 24-pin cable. The balanced connectors at both ends of the cable are identical. Type-C cables can be easily connected to a DFP or UFP without the user having to adjust the orientation of the connector. The Type-C system is designed to work seamlessly regardless of which end of the cable is connected to the device and whether the cable is properly oriented (i.e. there is no error in the way the Type -C cable is connected).
Backward compatibility with previous USB protocols
Type-C cables contain four USB 2.0 signals and the additional signals required to implement USB 3.0 and 3. USB 2.0 devices can be connected to Type-C cables and work as is. The additional functions and signals of Type-C cables are not used. The Type-C specification provides for three types of cables.
- Passive
- (EMA)/Electronically Marked Cable Assembly (EMCA)
- Managed Active Powered Cable (A passive Type-C cable is used to transmit USB 2.0 signals and is capable of providing 60 W of power.)
The Alternate mode of operation
The alternate mode allows third-party protocols to be transmitted over USB Type-C cables. This mode is negotiated on a port-by-port basis using a power transfer protocol.
Enhanced power supply negotiation
USB Power Delivery allows you to dynamically change the power settings of the USB connection. The default VBUS of 5V can be changed up to 20V. The maximum power provided by the port can also be changed up to 100W (using the appropriate electronically tagged Type-C cable).
Data Role Switching
Data roles (DFP and UFP) can be switched dynamically using the Power Delivery Protocol.
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