Complete USB pinout reference for Type-A, B, Micro, Mini, and USB-C connectors across USB 2.0, 3.0, and 3.1 standards. Includes signal functions, color codes, Vbus, D+/D-, TX/RX, CC, SBU, and design tips for engineers. Based on USB-IF specifications.
"Comprehensive pinout diagrams and technical descriptions for all major USB connector types, including Standard-A, B, Mini, Micro, and USB-C."
This web-based reference provides a detailed breakdown of USB connector pin configurations, signal functions, voltage levels, and color coding across generations: USB 2.0, USB 3.0, and USB 3.1 (Type-C). All information follows official specifications from the USB Implementers Forum (USB-IF).
Ideal for engineers, technicians, hobbyists, and students working with embedded systems, DIY electronics, or device repair.
Universal Serial Bus (USB) is a standardized interface for connecting peripherals to computers and mobile devices. It supports:
Data transfer
Power delivery (up to 240W in USB PD)
Device charging
Hot-swapping
Each USB version introduces new features:
USB 2.0: Up to 480 Mbps
USB 3.0: Up to 5 Gbps
USB 3.1 Gen 2: Up to 10 Gbps
USB 3.2 / USB4: Up to 40 Gbps
The physical connectors vary by type and generation, but all follow strict pin assignments.
| Connector | Pins | Use Case |
|---|---|---|
| USB 2.0 A/B | 4 pins | Hosts, printers, keyboards |
| Mini/Micro USB 2.0 | 5 pins | Older phones, cameras |
| USB 3.0 A/B | 9/11 pins | High-speed data, external drives |
| Micro USB 3.0 | 10 pins | Smartphones, tablets |
| USB 3.1 C (USB-C) | 24 pins | Reversible, high-power, fast data |
Note: USB-C supports reversibility, dual-role operation, and Power Delivery (PD).
Standard A: Standard B:┌─────────┐ ┌─────────┐│ 4 3 2 1 │ │ 1 2 │└─────────┘ └─────────┘ ↑ ↑ Plug View Plug View
| Pin | Signal | Color Code | Function |
|---|---|---|---|
| 1 | VCC (+5V) | Red | Power supply (up to 500mA) |
| 2 | Data - (D-) | White | Differential data pair (-) |
| 3 | Data + (D+) | Green | Differential data pair (+) |
| 4 | Ground | Black | Signal and power return |
Full-duplex communication using differential signaling
No ESD protection on host side? Use TVS diodes!
Standard A: Standard B:┌───────┐ ┌───────┐│ 1 2 3 4 5 │ │ 1 2 3 4 5 │└───────┘ └───────┘
| Pin | Signal | Function |
|---|---|---|
| 1 | VCC (+5V) | Power supply |
| 2 | Data - (D-) | USB 2.0 data negative |
| 3 | Data + (D+) | USB 2.0 data positive |
| 4 | None | Host detection: connected to ground in hosts, open in devices |
| 5 | Ground | Common ground |
Pin 4 enables automatic detection of host vs. slave
Used in older smartphones, GPS units, and digital cameras
Plug View:┌─────────────┐│ 5 6 7 8 9 ││ 4 3 2 1 │└─────────────┘
| Pin | Signal | Function |
|---|---|---|
| 1 | VCC (+5V) | Power supply |
| 2 | D- | USB 2.0 data negative |
| 3 | D+ | USB 2.0 data positive |
| 4 | GND | Power ground |
| 5 | RX2- | USB 3.0 receive line (-) |
| 6 | RX2+ | USB 3.0 receive line (+) |
| 7 | GND | Signal ground |
| 8 | TX2- | USB 3.0 transmit line (-) |
| 9 | TX2+ | USB 3.0 transmit line (+) |
Backward compatible with USB 2.0
Speed: Up to 5 Gbps (SuperSpeed)
Plug View:┌─────────────┐│ 9 8 7 6 5 ││ 10 11 ││ 4 3 │└─────────────┘
| Pin | Signal | Function |
|---|---|---|
| 1 | VCC (+5V) | Power supply |
| 2 | D- | USB 2.0 data negative |
| 3 | D+ | USB 2.0 data positive |
| 4 | GND | Power ground |
| 5 | TX2- | USB 3.0 transmit line (-) |
| 6 | TX2+ | USB 3.0 transmit line (+) |
| 7 | GND | Signal ground |
| 8 | RX2- | USB 3.0 receive line (-) |
| 9 | RX2+ | USB 3.0 receive line (+) |
| 10 | DPWR | Power provided by device (e.g., bus-powered hub) |
| 11 | GND | Return for DPWR |
Rarely used; replaced by USB-C in modern devices
Plug View:┌─────────────────────┐│ 1 0 9 8 7 6 ││ 5 4 3 2 1 │└─────────────────────┘
| Pin | Signal | Function |
|---|---|---|
| 1 | VCC (+5V) | Power supply |
| 2 | D- | USB 2.0 data negative |
| 3 | D+ | USB 2.0 data positive |
| 4 | ID | OTG identification (host/device role) |
| 5 | GND | Power ground |
| 6 | TX2- | USB 3.0 transmit line (-) |
| 7 | TX2+ | USB 3.0 transmit line (+) |
| 8 | GND | Signal ground |
| 9 | RX2- | USB 3.0 receive line (-) |
| 10 | RX2+ | USB 3.0 receive line (+) |
Used in early smartphones and tablets before USB-C adoption
Supports On-The-Go (OTG) mode
Plug View (Top Side):┌────────────────────────────┐│ 1 2 3 4 5 6 7 8 9 10 11 12 │└────────────────────────────┘│ 13 14 15 16 17 18 19 20 21 22 23 24 │└────────────────────────────┘
| Pin | Signal | Function |
|---|---|---|
| 1 | GND (A1) | Ground |
| 2 | TX1+ (A2) | SuperSpeed transmit (+) |
| 3 | TX1- (A3) | SuperSpeed transmit (-) |
| 4 | Vbus (A4) | +5V power supply |
| 5 | CC1 (A5) | Configuration Channel (detects orientation, power roles) |
| 6 | D+ (A6) | USB 2.0 data positive |
| 7 | D- (A7) | USB 2.0 data negative |
| 8 | SBU1 (A8) | Sideband use (for video/audio, alternate modes) |
| 9 | Vbus (A9) | +5V power supply (second path) |
| 10 | RX2- (A10) | SuperSpeed receive (-) |
| 11 | RX2+ (A11) | SuperSpeed receive (+) |
| 12 | GND (A12) | Ground |
| 13 | GND (B12) | Ground (symmetric side) |
| 14 | RX1+ (B11) | SuperSpeed receive (+) |
| 15 | RX1- (B10) | SuperSpeed receive (-) |
| 16 | Vbus (B9) | +5V power supply |
| 17 | SBU2 (B8) | Sideband use |
| 18 | D- (B7) | USB 2.0 data negative |
| 19 | D+ (B6) | USB 2.0 data positive |
| 20 | CC2 (B5) | Configuration Channel (backup) |
| 21 | Vbus (B4) | +5V power supply |
| 22 | TX2- (B3) | SuperSpeed transmit (-) |
| 23 | TX2+ (B2) | SuperSpeed transmit (+) |
| 24 | GND (B1) | Ground |
Fully reversible plug
Dual-role data flow (host/device)
Supports USB Power Delivery (up to 240W)
Supports DisplayPort and HDMI via Alternate Mode
Always route D+/D- as differential pairs with controlled impedance (~90Ω)
Keep Vbus trace short and wide for better current handling
Use TVS diodes on D+/D- lines for ESD protection
Add pull-up resistors on CC pins for proper negotiation
Follow USB-IF compliance guidelines for certification
USB 2.0: USB-IF Specification 2.0
USB 3.0: USB 3.0 Specification (Rev. 1.0)
USB 3.1: USB 3.1 Specification (Rev. 1.0)
USB-C: USB Type-C Specification (Rev. 2.1)
All modern devices must comply with these standards for interoperability.
No. Although USB-C connectors look identical, the internal wiring varies significantly. Some cables only support USB 2.0 speeds, while others include full SuperSpeed lanes, Thunderbolt support, or complete 240W power delivery capability. Always verify the cable specifications before purchasing.
The CC (Configuration Channel) pins are responsible for detecting cable insertion orientation, negotiating power roles (source/sink), and enabling Alternate Modes (such as DisplayPort video output). If the CC pins are not properly connected, the USB-C controller will not activate VBUS power delivery, and the interface will not function.
Yes. USB 3.0 is designed to be backward compatible with USB 2.0, but when plugged into a USB 2.0 port, the transfer speed will be limited to 480 Mbps. Conversely, a USB 2.0 device plugged into a USB 3.0 port will also work properly, running at USB 2.0 speed.
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