USB Type‑C Connector
Definition
USB Type‑C is a compact, reversible 24-contact connector. The same connector can carry USB 2.0, USB 3.2, USB4, power and selected Alternate Modes, but its shape alone does not guarantee a particular data rate, display mode or charging power. The two ports and the cable must support the requested feature.
Receptacle and plug front views
Receptacle (socket)
Plug
Both drawings are front views looking into the mating interface. Their left-to-right positions are therefore mirrored when the plug and receptacle face each other. Use the A/B contact identifiers, not only the apparent position, when checking a footprint.
A receptacle provides CC1 and CC2. A cable plug uses one contact as CC and may use the other as VCONN to power an electronically marked or active cable. VCONN is not a second configuration channel through the cable.
Receptacle pinout — 24 contacts
Signal groups: power · ground · USB 2.0 · high-speed pairs · configuration · sideband
| Pin A | Signal | Function | Pin B | Signal | Function |
|---|---|---|---|---|---|
| A1 | GND | Ground return | B12 | GND | Ground return |
| A2 | TX1+ | High-speed pair 1, positive | B11 | RX1+ | High-speed pair 1, positive |
| A3 | TX1− | High-speed pair 1, negative | B10 | RX1− | High-speed pair 1, negative |
| A4 | VBUS | Bus power | B9 | VBUS | Bus power |
| A5 | CC1 | Configuration channel 1 | B8 | SBU2 | Sideband use 2 |
| A6 | D+ | USB 2.0 data, positive | B7 | D− | USB 2.0 data, negative |
| A7 | D− | USB 2.0 data, negative | B6 | D+ | USB 2.0 data, positive |
| A8 | SBU1 | Sideband use 1 | B5 | CC2 | Configuration channel 2 |
| A9 | VBUS | Bus power | B4 | VBUS | Bus power |
| A10 | RX2− | High-speed pair 2, negative | B3 | TX2− | High-speed pair 2, negative |
| A11 | RX2+ | High-speed pair 2, positive | B2 | TX2+ | High-speed pair 2, positive |
| A12 | GND | Ground return | B1 | GND | Ground return |
The shell is the cable shield/chassis connection. TX/RX labels follow the standardized connector naming; the port controller and high-speed multiplexer route the active pairs according to cable orientation and operating mode.
What each signal group does
- VBUS and GND: four contacts each share the power current and provide a low-impedance return path. All corresponding contacts must be connected in a compliant design.
- D+ and D−: the USB 2.0 pair is duplicated on the receptacle so it works in either orientation. Join each same-name pair close to the receptacle and avoid long stubs.
- TX/RX high-speed pairs: carry USB 3.2 or USB4 traffic and may be reassigned by an Alternate Mode. An orientation-aware multiplexer is normally required.
- CC1 and CC2: detect attachment and orientation, establish source/sink and data roles, advertise Type‑C current, and carry USB Power Delivery communication on the active CC pin.
- SBU1 and SBU2: sideband conductors used only by defined Alternate Modes and USB4 functions; they are not general-purpose signals.
- VCONN: power delivered on the unused CC contact of the plug when an electronically marked or active cable requires it.
Data capabilities
| Technology | Maximum nominal data rate | Main contacts used |
|---|---|---|
| USB 2.0 Hi-Speed | 480 Mbit/s | D+ / D− |
| USB 3.2 Gen 1 | 5 Gbit/s | One high-speed lane |
| USB 3.2 Gen 2 | 10 Gbit/s | One high-speed lane |
| USB 3.2 Gen 2x2 | 20 Gbit/s | Two high-speed lanes |
| USB4 | Up to 80 Gbit/s | High-speed lanes plus configuration/sideband functions |
USB Type‑C is the connector system, not a performance label. A USB‑C port or cable may be limited to USB 2.0, omit video support, or support less power than another product with the same connector.
Voltage, current and USB Power Delivery
| Power mode | Nominal / negotiated voltage | Maximum current | Maximum power |
|---|---|---|---|
| Default USB power | 5 V | Depends on the USB mode and device state | Mode-dependent |
| USB Type‑C current | 5 V | 1.5 A | 7.5 W |
| USB Type‑C current | 5 V | 3 A | 15 W |
| USB PD SPR | Negotiated up to 20 V | Up to 5 A | 100 W |
| USB PD EPR | Negotiated up to 48 V | Up to 5 A | 240 W |
Never infer the available voltage or current from the connector alone. Values above 5 V require successful USB PD negotiation; operation above 3 A requires an appropriately electronically marked 5 A cable, and EPR operation requires an EPR-rated implementation and cable.
PCB design checklist
- Select the correct port role: source, sink or dual-role; implement the specified Rp/Rd behavior on CC1/CC2 with a suitable Type‑C/PD controller when needed.
- Route D+/D− and every high-speed pair as controlled differential pairs using the impedance, loss and skew limits of the implemented USB specification.
- Place the orientation multiplexer, ESD protection and AC-coupling components according to the controller and connector reference design; keep added capacitance and stubs low.
- Connect every VBUS and GND contact with copper sized for the advertised current. Add over-current, over-voltage and discharge protection required by the chosen role.
- Treat the shield-to-chassis connection as an EMC design decision; do not automatically substitute it for the signal ground.
- Confirm the connector footprint against the manufacturer's datasheet: shell tabs, mid-mount geometry and contact numbering vary between parts.