Mini-USB (Mini-B) Connector
5-pin rectangular connector
Standards: USB 2.0, USB OTG 1.0, USB Battery Charging 1.2
What is the Mini-USB pinout?
The Mini-USB (Mini-B) Connector has 5 pins. Pin 1 is VBUS (power). Pin 2 is D- (data). Pin 3 is D+ (data). Pin 4 is ID (data). Plus 1 more pins.
Standards: USB 2.0, USB OTG 1.0, USB Battery Charging 1.2
Pin Assignment Table
| Pin | Signal | Type | Description |
|---|---|---|---|
| 1 | VBUS | power | +5V Power (Red wire) - Up to 500mA |
| 2 | D- | data | Data Minus (White wire) |
| 3 | D+ | data | Data Plus (Green wire) |
| 4 | ID | data | ID Pin - Float for device mode, ground for OTG host mode |
| 5 | GND | ground | Ground (Black wire) |
Signal Types
Common Applications
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Use the pinout as a working reference now, then jump to the full library or the next workflow when you need it.
Map this connector into your BOM workflow →The Mini-USB connector has 5 pins: Pin 1 (VBUS, 5V), Pin 2 (D-), Pin 3 (D+), and Pin 4 (ID). Plus 1 more pins. Common in Digital cameras and MP3 players.
Mini-USB (Mini-B) Pinout Guide
Mini-USB (officially Mini-B) was introduced with USB 2.0 as the first compact USB connector designed for portable devices. The 5-pin design includes the standard USB signals (VBUS, D-, D+, GND) plus an ID pin that enables USB On-The-Go (OTG) functionality. In Mini-B connectors, the ID pin is typically left floating (unconnected), identifying the device as a peripheral. Mini-A connectors (now deprecated) had the ID pin grounded, identifying the device as a host. The trapezoidal shape with beveled edges makes Mini-USB more durable than Micro-USB but larger, which led to its replacement in smartphones and smaller devices.
Wiring Tips & Best Practices
Standard wire colors follow USB conventions: Red = VBUS (+5V), White = D- (Data Minus), Green = D+ (Data Plus), Black = GND (Ground). The ID pin (Pin 4) is typically unconnected in standard Mini-B cables. For OTG functionality, the ID pin must be grounded at the host end through a resistance of 10 ohms or less. For charging-only cables, D+ and D- may be shorted together (Apple devices) or connected to specific resistor dividers to signal charging capability. Mini-USB connectors can handle up to 500mA at 5V per USB 2.0 specification.
Common Issues
The Mini-USB connector is relatively robust but the internal contacts can wear after thousands of insertion cycles, causing intermittent connections. Data-only vs charging issues: If the device charges but won't transfer data, the cable may be charge-only (missing D+/D- wires). OTG not working: Verify the ID pin is properly grounded in the OTG cable. Some devices require specific ID pin resistance values for proper OTG detection. Mini-USB to Micro-USB adapters exist but may not support OTG due to ID pin routing. Bent or damaged connector pins from forcing insertion at wrong angle - always align carefully before inserting.
Why Use Interactive Diagrams?
- Accuracy: Hover over pins to see exact signal names and descriptions
- Clarity: Color-coded by signal type (power, ground, data)
- Printable: Export clean diagrams for shop floor reference