The USB Type-C Specification 1.0 was published by the USB Implementers Forum (USB-IF) and was finalized in August 2014. It was developed at roughly the same time as the USB 3.1 specification.
If a product implements USB Type-C, it does not necessarily support USB 3.1 or USB Power Delivery.
The USB Type-C connectors connect to both hosts and devices, replacing various Type-B and Type-A connectors and cables with a standard meant to be future-proof. The 24-pin double-sided connector is slightly larger than the micro-B connector, with a USB Type-C port measuring 8.4 millimetres (0.33 in) by 2.6 millimetres (0.10 in). The connector provides four power/ground pairs, two differential pairs for non-SuperSpeed data (though only one pair is populated in a USB Type-C cable), four pairs for SuperSpeed data bus (twice as much as on the USB3 connector), two "sideband use" pins, and two configuration pins for cable orientation detection, dedicated biphase mark code (BMC) configuration data channel, and VCONN +5 V power for active cables. Connecting an older device to a host with a USB Type-C receptacle requires a cable or adapter with a Type-A or Type-B plug or receptacle on one end and a USB Type-C plug on the other end. Legacy adapters with a USB Type-C receptacle are "not defined or allowed" by the specification, due to their being able to create "many invalid and potentially unsafe" cable combinations.
USB 3.1 Type-C to Type-C cables are considered full-featured USB Type-C cables and must be active, electronically marked cables that contain a chip with an ID function based on the configuration channel and vendor-defined messages (VDMs) from the USB Power Delivery 2.0 specification. USB Type-C devices may optionally support bus power currents of 1.5 A and 3.0 A (at 5 V) in addition to baseline bus power provision; power sources can either advertise increased USB current through the configuration channel, or they can support the full power delivery specification using both BMC-coded configuration line and legacy BFSK-coded VBUS line. USB 2.0 Type-C to Type-C cables are only required to contain e-marker chips if the cable supports 5A instead of the default 3A, which requires USB Power Delivery support.
Devices may be hosts or peripherals. Some, such as mobile phones, can take either role depending on what kind is detected on the other end. These types of ports are called Dual-Role-Data (DRD). When two such devices are connected, the roles are randomly assigned but a swap can be commanded from either end. Furthermore, dual-role devices that support USB Power Delivery may independently and dynamically swap data and power roles using the Data Role Swap or Power Role Swap processes. This allows for charge-through hub or docking station applications where the Type-C device acts as a USB data host while acting as a power consumer rather than a source.
An Alternate Mode dedicates some of the physical wires in the USB Type-C cable for direct device-to-host transmission of alternate data protocols. The four high-speed lanes, two sideband pins, and (for dock, detachable device and permanent cable applications only) two non-SuperSpeed data pins and one configuration pin can be used for alternate mode transmission. The modes are configured using VDMs through the configuration channel.
Name | Logo | Date | Supporting |
---|---|---|---|
DisplayPort Alternate Mode | published in September 2014 | DisplayPort 1.3 (includes USB 3.1). | |
MHL Alternate Mode | announced in November 2014 | MHL 1.0, 2.0, 3.0 and superMHL. | |
Thunderbolt Alternate Mode | announced in June 2015 | Thunderbolt 3 (includes DisplayPort Alternate Mode). | |
HDMI Alternate Mode | announced in September 2016 | HDMI 1.4b. |
Other serial protocols like PCI Express and Base-T Ethernet are possible.
Compliant Alternate Mode hosts and sinks can be connected with regular passive USB 3.1 Type-C cables or passive converter cables/adapters:
Alternate Mode DisplayPort, MHL, HDMI and Thunderbolt 20 Gbps ports can be interconnected with standard "full-featured" USB 3.1 Type-C cables. Thunderbolt3 (40Gbps) protocol requires specially tested reduced length cables that are certified and electronically marked for high-speed, similarly to high-power USB Power Delivery.
USB 3.1 Type-C adapter cable (plug) or adapter (socket)
These cables/adapters typically contain a DisplayPort plug, HDMI plug or socket, or superMHL plug on the other end.
Alternate Mode does not use USB 2.0 lanes and configuration channel pin, so USB 2.0 and USB Power Delivery protocols are always available. DisplayPort (Thunderbolt 3) Alternate Mode can simultaneously trasmist USB 3.1 signal using two of the four SuperSpeed lanes.
A Type-C device is not required to support any Alternate Mode. The USB Implementers Forum is working with its Alternate Mode partners to make sure that ports are properly labelled with respective logos.
Protocol conversion requires active cables/adapters which contain powered ICs. DisplayPort Alternate Mode (and DisplayPort Alternate Mode support within the Thunderbolt 3 Alternate Mode) can be used for active conversion to Analog VGA, component video, dual-link DVI, and HDMI; passive HDMI 2.0 conversion using Dual-Mode DisplayPort (DP++) is not supported. MHL Alternate Mode can be used for active conversion to HDMI. HDMI Alternate Mode does not define protocol conversion.
As of December 2016, existing USB Type-C ports and USB-HDMI/USB-DisplayPort convertors use regular USB 2.0/3.1 protocols; Type-C Alternate Mode compliant products are expected to appear during H1 2017.
Pin | Name | Description | Pin | Name | Description | ||
---|---|---|---|---|---|---|---|
A1 | GND | Ground return | B12 | GND | Ground return | ||
A2 | SSTXp1 | SuperSpeed differential pair #1, TX, positive | B11 | SSRXp1 | SuperSpeed differential pair #2, RX, positive | ||
A3 | SSTXn1 | SuperSpeed differential pair #1, TX, negative | B10 | SSRXn1 | SuperSpeed differential pair #2, RX, negative | ||
A4 | VBUS | Bus power | B9 | VBUS | Bus power | ||
A5 | CC1 | Configuration channel | B8 | SBU2 | Sideband use (SBU) | ||
A6 | Dp1 | Non-SuperSpeed differential pair, position 1, positive | B7 | Dn2 | Non-SuperSpeed differential pair, position 2, negative | ||
A7 | Dn1 | Non-SuperSpeed differential pair, position 1, negative | B6 | Dp2 | Non-SuperSpeed differential pair, position 2, positive | ||
A8 | SBU1 | Sideband use (SBU) | B5 | CC2 | Configuration channel | ||
A9 | VBUS | Bus power | B4 | VBUS | Bus power | ||
A10 | SSRXn2 | SuperSpeed differential pair #4, RX, negative | B3 | SSTXn2 | SuperSpeed differential pair #3, TX, negative | ||
A11 | SSRXp2 | SuperSpeed differential pair #4, RX, positive | B2 | SSTXp2 | SuperSpeed differential pair #3, TX, positive | ||
A12 | GND | Ground return | B1 | GND | Ground return | ||
|
USB Type-C receptacle pinout end-on view
USB Type-C plug pinout end-on view
The capabilities of USB Type-C cables depends on (1) USB modes supported, (2) Amount of power supported for charging and (3) Alternate modes supported by the cable. There are cables which support only USB 2.0 with up to 480 Mbps data rate. The cables which support USB 3.0/USB 3.1 Gen 1 can handle up to 5 Gbps data rate at full duplex and are marked as super-speed cable. The cables which support USB 3.1 Gen 2 handle up to 10 Gbps data rate at full duplex and are marked as super-speed+. The charging capacity of USB Type-C cables may go up to 5A (100W), but 3A (i.e. up to 60W) cables are commonly available.
The support for alternate modes requires extra connections for optional pins as well - like additional super-speed lanes, and 'side-band use' pins. The support for alternate modes usually adds an extra bandwidth requirement to the cable - in addition to the bandwidth already needed for USB data transfer. For example:
A USB 3.1 Gen 2 super-speed+ cable supporting 10 Gbps data rate has an aggregate bandwidth capacity of 20 Gbps (i.e. 10 Gbps transmit + 10 Gbps receive).
A USB 3.0 data stream of 5 Gbps has a bandwidth requirement of 10 Gbps (i.e. 5 Gbps transmit + 5 Gbps receive).
A 4K UHD 30fps video stream has a bandwidth requirement of 10 Gbps.
A 4K UHD 60fps video stream has a bandwidth requirement of 18 Gbps.
Hence, a USB 3.1 super-speed+ cable can safely carry a simultaneous 5 Gbps data stream and 4K UHD 30fps video stream at once (i.e. 10 Gbps data stream + 10 Gbps video stream roughly fits in to 20 Gbps cable capacity). Or it can carry a 4K UHD 60fps video stream alone. There are USB-IF certification programs available for USB Type-C cables and it is recommended to use USB-IF certified cables.
Plug 1, USB Type-C | USB Type-C cable | Plug 2, USB Type-C | ||||||
---|---|---|---|---|---|---|---|---|
Pin | Name | Wire colour | No | Name | Description | 2.0 | Pin | Name |
Shell | Shield | Braid | Braid | Shield | Cable external braid | ✓ | Shell | Shield |
A1, B12, B1, A12 | GND | Tin-plated | 1 | GND_PWRrt1 | Ground for power return | ✓ | A1, B12, B1, A12 | GND |
16 | GND_PWRrt2 | ✗ | ||||||
A4, B9, B4, A9 | VBUS | Red | 2 | PWR_VBUS1 | VBUS power | ✓ | A4, B9, B4, A9 | VBUS |
17 | PWR_VBUS2 | ✗ | ||||||
B5 | VCONN | Yellow | 18 | PWR_VCONN | VCONN power, for active cables | ✓ | B5 | VCONN |
A5 | CC | Blue | 3 | CC | Configuration channel | ✓ | A5 | CC |
A6 | Dp1 | White | 4 | UTP_Dp | Unshielded twisted pair, positive | ✓ | A6 | Dp1 |
A7 | Dn1 | Green | 5 | UTP_Dn | Unshielded twisted pair, negative | ✓ | A7 | Dn1 |
A8 | SBU1 | Red | 14 | SBU_A | Sideband use A | ✗ | B8 | SBU2 |
B8 | SBU2 | Black | 15 | SBU_B | Sideband use B | ✗ | A8 | SBU1 |
A2 | SSTXp1 | Yellow | 6 | SDPp1 | Shielded differential pair #1, positive | ✗ | B11 | SSRXp1 |
A3 | SSTXn1 | Brown | 7 | SDPn1 | Shielded differential pair #1, negative | ✗ | B10 | SSRXn1 |
B11 | SSRXp1 | Green | 8 | SDPp2 | Shielded differential pair #2, positive | ✗ | A2 | SSTXp1 |
B10 | SSRXn1 | Orange | 9 | SDPn2 | Shielded differential pair #2, negative | ✗ | A3 | SSTXn1 |
B2 | SSTXp2 | White | 10 | SDPp3 | Shielded differential pair #3, positive | ✗ | A11 | SSRXp2 |
B3 | SSTXn2 | Black[d] | 11 | SDPn3 | Shielded differential pair #3, negative | ✗ | A10 | SSRXn2 |
A11 | SSRXp2 | Red | 12 | SDPp4 | Shielded differential pair #4, positive | ✗ | B2 | SSTXp2 |
A10 | SSRXn2 | Blue[d] | 13 | SDPn4 | Shielded differential pair #4, negative | ✗ | B3 | SSTXn2 |
USB 2.0 Type-C cables do not include wires for SuperSpeed, sideband use, or as great power capacity.
VCONN must not traverse end-to-end through the cable. Some isolation method must be used.
There is only a single differential pair for non-SuperSpeed data in the cable, which is connected to A6 and A7. Contacts B6 and B7 should not be present in the plug.
|
Windows 10 and Windows 10 Mobile supports USB 3.1, USB Type-C, alternate modes, billboard,[clarification needed] power delivery, audio accessory and USB Dual Role support.
Windows 8.1 added USB type-C and billboard support in an update.
OS X Yosemite supports USB 3.1, USB Type-C, alternate modes and power delivery.
Android Marshmallow works with USB 3.1 and USB Type-C.
Chrome OS supports USB 3.1 and USB Type-C starting with the Chromebook Pixel 2015 and supports alternate modes, power delivery, and USB Dual Role support
An increasing number of motherboards, notebooks, tablet computers, smartphones, hard disk drives, USB hubs and other devices released from 2014 onwards feature Type-C receptacles.
Some non-compliant cables with a Type-C connector on one end and a legacy Standard-A plug or Micro-B receptacle on the other end incorrectly terminate the Configuration Channel (CC) with a 10kΩ pullup to VBUS instead of the specification mandated 56kΩ pullup, causing a device connected to the cable to incorrectly determine the amount of power it is permitted to draw from the cable. Cables with this issue may not work properly with certain products, including Apple and Google products, and may even damage power sources such as chargers, hubs, or PC USB ports.
USB Type-C Locking Connector Specification
USB Audio Device Class 3.0 Specification / USB Audio over USB Type-C
USB Type-C Cable and Connector Language Usage Guidelines
From Wikipedia, the free encyclopedia