What is a USB B-type connector?
USB connectors have become synonymous with electronic device connections, like flash drives and smartphone charging.
But these connectors have different designs, which the industry labels using the letters A, B, and C.
We’ll cover everything you should know about the USB B-type connector below, including its properties, sub-types, pinout, and more. Let’s get right into it!
Table of Contents
- A Brief Look at USB Connectors
- What Is a USB B-Type Connector?
- USB B-Type Connector Standards or Versions
- USB B-Type Color Coding
- USB B-Type Connector Pinout
- Wrap Up
A Brief Look at USB Connectors
USB connections have a directed design, meaning the link has one downstream-facing port that provides power and an upstream-facing port.
This connection design is different from other power bi-directional computing data buses like ethernet, and it helps prevent overloading, which can damage the devices.
Therefore, USB cable assemblies usually have a different connector plug on each end. The cable can have one A or C plug on one end and a B or C plug on the other.
A printer cable with a USB type-A connector for the computer side and a type-B plug for the printer side
The two types help avoid the accidental connection of the cable to two power supply sources, which prevents the overloading mentioned above.
These two plugs fit into receptacles (USB ports) on the peripheral and host devices.
But there is an exception. This directed topology does not apply to multi-purpose USB connections like OTG and USB-powered Wi-Fi routers.
These links can have A-to-A or B-to-B cables (similar plugs on both ends).
Another thing. Micro and mini formats of type A and B USB connectors can connect to the AB USB port on the device.
The receptacle accepts both, and the plug type determines its behavior.
What Is a USB B-Type Connector?
Since it is part of the directed topology design, a USB B-type connector allows bi-directional data flow, but power goes only one way (host to peripheral device).
Physically, this connector is smaller than type A and has a square protrusion with slightly beveled corners on the top ends.
A USB B-type plug and socket
Type-B connectors are not popular in computer-to-mobile phone connections, but you must have encountered some if you use external hard drives, scanners, and printers.
These cables have the type-A connector on the computer end and the type-B connector on these devices.
But tinier mini, micro, and reversible type-C connectors are gradually replacing the large, standard A and B connectors.
However, this description defines the standard type-B USB connector. Mini and micro USB-B are different.
Mini USB Type-B Plug
These connectors come in two configurations. The 5-pin type has a thick width (0.12 x 0.28 inches), and the sides narrow towards the top like a trapezoid.
This cable was the standard for transferring data to and from PDAs and early smartphones, but most manufacturers abandoned it due to its large size.
It could not fit the modern, compact mobile devices.
A USB mini type-B plug and port
The 4-pin mini type-B plug is an unofficial connector that lacked the 5th ID pin to support OTG.
It is typical in digital cameras, and its design resembles the standard type-B plug but with a smaller form factor.
Micro USB Type-B Plug
USB-IF announced this connector in January 2007 to integrate into thinner mobile devices.
It has the same width as the mini connector but with almost half the thickness (0.071 x 0.27 inches).
A micro USB type-B connector
This compact size made this type-B connector typical in cell phones, PDAs, and digital cameras.
The plug contains five pins (supports OTG) and has a transfer rate of 480Mbps.
USB B-Type Connector Standards or Versions
The USB type-B connectors are only available in four versions of this data bus technology.
USB 1.1
USB types A and B are the pioneer connectors for the USB computing data bus, and they began as version 1.1 in 1998.
This full-speed USB standard has a maximum data transfer speed of 12 Mbps, and this specification covers a 3-meter cable length.
The directed topology for the USB cable’s configuration is type-A to type-B, and the maximum power output to the peripheral electronic device is 500mA at 2.5V.
USB 2.0
USB 2.0 (or high-speed USB) came into the market in 2000, increasing the maximum data transfer speed to 480 Mbps.
It covers the standard, micro, and mini B-type connectors, and the specification’s cable length is 5 meters.
Black USB 2.0 type-A and type-B connectors
This connector also supports the directed topology (type-A to type-B), with the maximum power output increasing to 1.8 amps at 2.5V.
USB 3.0
USB 3.0 followed in 2008 but only applied to the standard and micro USB type-B connectors. You can identify these connectors using the blue plastic tongue inside the metal shell.
A USB 3.0 type-B connector (note the blue plastic tongue)
Also known as SuperSpeed, this standard increased the data transmission speed exponentially to 5 Gbps, but the power flow remained directional.
Also, the maximum power output remained unchanged.
USB 3.1
USB 3.1 is the last version to apply to type B connectors. The fourth generation (USB 4.0) only applies to type-C.
Also known as SuperSpeed+, USB 3.1 doubled the maximum data transfer speed to 10 Gbps and increased the maximum power output to 5 amps at 20V.
This upgrade came into the market in 2013 and only came in the standard and micro type-B connectors.
USB 3.0 vs. 3.1 (note the tongue color difference).
The specification’s cable length remained the same as that of USB 3.0, which is 3 meters.
USB B-Type Color Coding
USB ports and connectors contain color codes on the plastic tongue that primarily differentiate their versions.
Since these B-type connectors only go up to generation 3.1, we’ll list the universal color codes up to that point.
- Black or white for USB versions 1.1 and 2.0 (full and high speed)
- Blue (Pantone) for the 3.0 standard (SuperSpeed)
- Teal blue for USB version 3.1 (SuperSpeed+)
There’s also a green USB type-B Qualcomm Quick-Charge connector.
A USB micro type-B SuperSpeed connector
USB B-Type Connector Pinout
Standard USB B-type connectors under versions 1.1 and 2.0 have the same pinout. They contain two power wires and two wires for differential serial data signal transmission.
| Pin | Name | Wire Color | Description |
| 1 | V bus (positive power voltage) | Orange or red | +5V |
| 2 | D- | Gold or white | Data low |
| 3 | D+ | Green | Data high |
| 4 | GND | Blue or black | Ground link |
Mini and micro USB B-type connectors have an extra pin that serves as an ID connection for client or OTG identification.
The plug moves the GND pin to number five to place this ID pin as the fourth one in the lineup.
These pins increased to 10 in version 3.0 to support high-speed data transmission.
The standard introduces two extra differential pairs to enable SuperSpeed full-duplex data transfer, similar to what you get with single-lane PCI-e or Serial ATA.
A USB cable with type-A and type-B 3.0 connectors (note the blue tongue)
These four wires (two differential pairs) include the following.
- SuperSpeed transmit – (pin 6)
- SuperSpeed transmit + (pin 7)
- SuperSpeed receive – (pin 9)
- SuperSpeed receive + (pin 10)
Pin 8 is an extra ground connection.
Wrap Up
Looking at a USB type-B plug or port, you won’t know the underlying physical setup that makes the connection work.
But this article clarifies that information, especially the changes through the generations from version 1.1 to 3.0.
USB 4.0 (type-C) will phase out these type-B connectors at some point, but they are still relevant in the market today.
So reach out if you need this cable for your car, printer, or other peripheral devices. We’ll recommend the best you can get in the market.
