What is USB Type-C?
The USB TYPE-C standard has been developed to meet the ever growing needs of
connectivity between modern devices. USB TYPE-C connectivity provides both power
and data exchange at higher power levels and higher speeds compared to the legacy
USB standard. The mechanical design of the USB TYPE-C connector and receptacle has
also been improved, to enable smaller form factor and make the connection more user-friendly.
Compared to old USB 1.x/2.0 standard, USB Type-C connector is a reversible plug
in smaller physical size which supports high data speed up to 10Gbps and up to 100W
with power delivery.
Read more for the comparison table of all USB
standards from USB 1.x/2.0 standard to USB Type-C in terms of connector type, connection
definition, data speed and supporting voltage/current.
Advantages of USB TYPE-C standard
- USB TYPE-C plug is reversible, so it can be plugged in either way;
the pinning is laid out in such a way that power connections will always meet
correctly. Since the receptacle has two rows of D+ and D- where the two D+ lines
and the two D- lines are connected together so the D+ and D- will always meet-up.
The high speed TX lines and RX lines cannot be connected together. Therefore
the USB TYPE-C CC lines are used to identify the cable orientation and will
configure the TX/RX hardware to work correctly. Diagram below shows USB TYPE-C receptacle and cable plug pinning.
- Another differences between older USB standard and the new USB TYPE-C
standard is the dual role capability: USB TYPE-C cables have identical
plugs on either side of the cable, which means that devices connected together
have to tell each other who will be acting as host and who will be acting as
device. Note that these roles need to be determined for both data and power
after connection of the cable: For data transmission, the host is called the
Downstream Facing Port (DFP) and the device is called the Upstream Facing Port
(UFP). For power, the power provider is the Source and power consumer is the
Sink. Some applications can have Dual Roles for Data (DRD) and Dual Role for
Power (DRP). The CC lines will be used to define the power role of the two connected
devices during connection.
- Another advantage of the USB TYPE-C system is its higher power capability.
Whereas the legacy USB was able to provide 2.5W only, USB TYPE-C is able to
provide up to 5V/3A, 15W max, and with Power Delivery, the voltage & current
range is increased to 20V/5A for maximum power of 100W. This makes it possible
to power larger devices from the USB PD port, like monitors, and also allows
charging devices with large battery packs like notebook computers. The new USB
PD 3.0 standard also supports Programmable Power Supply (PPS) which allows fine
adjustment of the bus voltage and current, and even allows lower voltage than
5V; PPS Vbus can be adjusted down to 3V which is very useful in Direct Charge
systems where the Bus voltage is directly connected to the battery for highest
efficiency charging. Standard type-C cables are rated for currents up to 3A.
For higher currents up to 5A, special E-marked cables need to be used. These
cables include an E-mark IC that identifies the cables capability via the CC
line. E-mark ICs require a 5V power supply to be applied to the cable VCONN
pin via one of the CC wires.
- The Super Speed + 10Gbps data rate via the TX/RX pairs
makes it possible to transfer signals that previously needed dedicated cables,
like HDMI / Display Port/Thunderbolt, and allows 4k video to be transferred
over USB TYPE-C. HDMI signal transfer via USB TYPE-C cables requires special
use of the data transfer pairs in the cable, which is called Alternate Mode.
Read more to find out how USB TYPE-C configures data and power.
Examples of USB TYPE-C applications and related Richtek power management ICs.
Please click each diagram for product details and
find design examples here