Why are there no B6 and B7 Pins on the PCB of the Type-C male connector?
Nov 24, 2023
Why are there no B6 and B7 Pins on the PCB of the Type-C male connector?We know that the USB Type-C connector has a total of 24 Pins, 12 Pins on the A side (A1, A2, A3,A4, A5, A6, A7,A8, A9, A10, A11, A12), and 12 Pins on the B side (B1, B2, B3, B4, B5, B6, B7, B8, B9, B10, B11, B12), but why are there no B6, B7 Pins on the PCB of the Type-C male connector?
USB Type-C Male connector
USB Type-C Female connector
It can be said that the USB Type-C connector is the terminator of connectors. It integrates many functions such as power delivery, audio, video, and data transmission. At the same time, the USB Type-C connector is very small, its width is only about two-thirds of the USB Type-A connector, and its thickness is about half that of USB Type-A. If there are 24 Pins designed on such a small connector, then there must be very dense wires on the PCB of the Type-C connector.
Connectors replaced by USB Type-C
At the same time, the USB Type-C cable supports reversible plugging, super fast charging up to 20V, 5A, and complex role switching. This requires that there are some electronic components on the PCB of the Type-C connector, such as E-Mark chips, logic chips, and different resistors, capacitors, etc. These electronic components all need a place to install them. Designers of USB Type-C connectors must consider where to install them from the beginning.
B6, B7 Pins on the PCB of the Type-C male connector are empty
We carefully observed the A and B sides of the USB Type-C connector and found that the layout of their Pins is basically the same. Due to the need to support large currents, 4 VBUS Pins (A4, A9, and B4, B9) and 4 GND Pins (A1, A12, and B1, B12) are always working at the same time. However, four sets of high-speed signal wires (A2&A3, A10&A11, B2&B3, B10&B11,) and A5, B5 will encounter complex switching issues due to the different directions when Type-C male plug inserted into female socket.
The simplest of all 24 Pins is the USB 2.0 signal set, A6 and A7. If connect A6 and B6 together and A7 and B7 together on the Type-C female socket, then when the Type-C male plug is connected to the female socket, regardless of the direction of the connection, the USB 2.0 signal set can work successfully. Therefore, B6 and B7 on the Type-C male connector become unnecessary and can be eliminated to make room for the electronic components that need to be mounted on the PCB. This is why there are no B6, B7 Pins on the PCB of the Type-C male connector
B6, B7 Pins on the PCB of the Type-C male connector are empty