USB Type-C Pinout & Wiring Diagram: 24-Pin Explained (2026)

The USB C pinout defines how each of the 24 pins in a USB Type-C connector functions, carrying data, power, and configuration signals. Whether you are designing a PCB layout, troubleshooting a charging issue, or selecting connectors for a new product, understanding the USB C pinout is essential. This guide breaks down every pin, its function, and practical wiring considerations, based on VITALCONN's experience as a manufacturer of 93+ USB-C connector models.

The USB C pinout is symmetrical by design, meaning the connector works regardless of insertion orientation. This is achieved through mirrored pin pairs on the receptacle. Let us examine each pin group in detail.

USB C Pinout: Complete 24-Pin Reference Table

The USB C pinout consists of 24 pins arranged in a specific pattern. Here is the complete pin assignment for a full-featured 24-pin USB Type-C receptacle:

USB C Pinout: Functional Pin Groups Explained

Power Pins: VBUS and GND

In the USB C pinout, VBUS pins (A4, A9, B4, B9) carry bus power from 5V to 48V, supporting up to 5A (PD 3.1, 240W). GND pins (A1, A12, B1, B12) provide the return path and are connected to the connector shield. The four VBUS pins are paralleled internally to distribute current and reduce contact resistance, which is critical at 5A loads.

VITALCONN's 24-pin USB-C connectors use 0.25mm-thick phosphor bronze for VBUS and GND contacts, achieving <20mΩ contact resistance, 33% below the USB-IF maximum of 30mΩ.

Configuration Channel (CC) Pins

CC1 (A5) and CC2 (B5) are the most important pins in the USB C pinout for functionality. They serve three critical functions:

• Orientation: Detecting cable orientation and direction (which side is plugged in)
• Current Advertisement: Determining current capacity (default 500mA, 1.5A, or 3A) via pull-up resistor value
• PD Communication: Carrying USB Power Delivery (PD) messages via BMC (Biphase Mark Coding) modulation

When a plug is inserted, one CC pin contacts the cable's CC wire while the other contacts VCONN (used to power electronically marked cables). The host reads the voltage on CC to determine orientation and current capability.

SuperSpeed Data Lanes: TX and RX

The USB C pinout includes four high-speed differential pairs for SuperSpeed data:

• Lane 1 TX: TX1+/TX1- (A2/A3): Transmit lane 1
• Lane 1 RX: RX1+/RX1- (B11/B10): Receive lane 1
• Lane 2 TX: TX2+/TX2- (B2/B3): Transmit lane 2
• Lane 2 RX: RX2+/RX2- (A11/A10): Receive lane 2

These lanes support USB 3.0 (5Gbps), USB 3.1 (10Gbps), USB 3.2 (20Gbps), and USB4 (40Gbps). Only one TX/RX pair pair is active at a time, determined by plug orientation. In USB4 v2.0, all four pairs can be used simultaneously for 80Gbps.

USB 2.0 Data Pins: D+ and D-

D+ (A6/B6) and D- (A7/B7) provide USB 2.0 compatibility at 480Mbps. These pins exist on both sides of the USB C pinout (mirrored), so only one set is active. They ensure backward compatibility with legacy USB devices and are the only data pins present on 12-pin and 14-pin connectors.

Sideband Use (SBU) Pins

SBU1 (A8) and SBU2 (B8) are auxiliary pins used in Alternate Modes. In DisplayPort Alt Mode, SBU carries the AUX channel for EDID and link training. In analog audio mode, SBU carries microphone and speaker signals. Only one SBU pin is active depending on orientation.

USB C Pinout Wiring Guide: Practical PCB Layout Tips

Designing a PCB with USB Type-C requires careful attention to the USB C pinout layout. Here are practical recommendations from VITALCONN's engineering team:

1. Power Routing: Route VBUS and GND with 1oz copper, minimum 0.3mm trace width for 3A, 0.5mm for 5A. Use copper pours for GND.
2. High-Speed: Route TX/RX differential pairs with 90-ohm differential impedance, 0.15mm trace width, 0.1mm spacing. Keep length mismatch <5 mils.
3. CC Pins: Place CC1 and CC2 near the connector edge, route to PD controller with 0.15mm traces. Add 0.1μF decoupling cap.
4. USB 2.0: Route D+/D- as 45-ohm differential pair. Add ESD protection diodes within 3mm of connector pins.
5. Grounding: Use a solid GND plane directly under the connector. Stitch vias around the connector perimeter for shielding.
6. ESD Protection: Place TVS diodes on VBUS, CC, D+/D-, and SBU pins. Use components rated for the maximum PD voltage (48V for PD 3.1).

USB C Pinout and Alternate Modes

The USB C pinout supports Alternate Modes, where certain pins are repurposed for non-USB protocols. The CC pins negotiate which Alt Mode to enter during connection:

For a comprehensive overview of USB-C connector types, see our Ultimate Guide to USB Type-C Connectors.

Frequently Asked Questions (FAQ)