Mini-USB (Mini-B) Pinout
The 5-pin Mini-B connector - USB 2.0 data, power, and an OTG ID pin.
Overview
Mini-USB (almost always Mini-B) is the small 5-pin connector once common on cameras, MP3 players, and modules. It adds an ID pin to the standard four signals for USB On-The-Go role detection.
For a normal device you only need VBUS, D-, D+, and GND. ID floating = peripheral; ID tied to GND = OTG host.
Pinout
| Pin | Name | Function | Description |
|---|---|---|---|
| 1 | VBUS | POWER | +5 V bus power |
| 2 | D- | USB2 / DATA | USB 2.0 data, negative |
| 3 | D+ | USB2 / DATA | USB 2.0 data, positive |
| 4 | ID | GND | OTG role select: floating = device, GND = host |
| 5 | GND | GND | Ground |
Notes
- The 5th (ID) pin distinguishes Mini from the 4-pin standard connectors.
- Mini-A is deprecated; 'Mini-USB' in practice means Mini-B.
Reference: USB-IF / Wikipedia - USB hardware· verified 2026-06-27