What is a USB 3.1 Type C?

What is a USB 3.1 Type C?

USB-C basically describes the plug’s shape. For example, if you use an Android phone the connector shape of the previous standard is USB-B and the flat one on your computer is called USB-A. The connector itself can support various exciting new USB standard like USB 3.1 and USB power delivery.

As technology moved from USB 1 to USB 2 and on to modern USB 3, the standard USB-A connector has stayed the same, providing backward compatibility without the need for adapters. USB Type-C is a new connector standard that’s about a third the size of an old USB Type-A plug.

This is a single connector standard that can connect an external hard drive to your computer or charging your laptop, like the Apple Macbook. This one tiny connector can be small and fit into a mobile device like a cell phone, or be the powerful port you use to connect all the peripherals to your laptop. All this, and it is it reversible to boot; so no more fumbling around with the connector the wrong way.

espite their similar shapes, Apple’s Lightning port is completely proprietary and won’t work with superior USB-C connector. Lightning ports had limited acceptance beyond Apple products and thanks to USB-C, are soon be as obscure as firewire.

USB 3.1 Type C Specification

Small size, support for forward and reverse insertion, fast (10Gb). This small is for the USB interface on the previous computer, the actual relative
The microUSB on the android machine is still a bit bigger:
Features
USB Type-C: 8.3mmx2.5mm
microUSB: 7.4mmx2.35mm
And lightning: 7.5mmx2.5mm
Therefore, I can't see the advantages of USB Type-C on handheld devices in terms of size. And the speed can only see if the video transmission is needed.
Pin definition

It can be seen that the data transmission mainly has two sets of differential signals of TX/RX, and CC1 and CC2 are two key pins, which have many functions:
• Detect connections, distinguish between front and back, distinguish between DFP and UFP, that is, master and slave
• Configure Vbus with USB Type-C and USB Power Delivery modes
• Configure Vconn. When there is a chip in the cable, a cc transmits a signal, and a cc becomes a power supply Vconn.
• Configure other modes, such as when connecting audio accessories, dp, pcie
There are 4 power and ground, which is why you can support up to 100W.

Don't watch USB Type-C seem to support up to 20V/5A, in fact this requires USB PD, and support for USB PD requires extra
Pd chip, so don't think that it is a USB Type-C interface that can support 20V/5A.
Of course, there should be chips that are integrated together in the future.
The auxiliary signals sub1 and sub2 (Side band use) are used in certain transmission modes.
d+ and d- are standard before USB compatibility.
Here to talk about, USB3.0 only has a set of RX/TX, the speed is 5Gb, USB Type-C can be inserted into two groups in order to ensure the positive and negative,
But in fact, data transmission still only uses a set of RX/TX, the speed has reached 10Gb. If the agreement is later upgraded, both groups will pass it.
It is 20Gb like DisplayPort.

Work Process

The DFP (Downstream Facing Port) is the main picture, and the UFP (Upstream Facing Port) is the slave. In addition to DFP, UFP,
There is also a DRP (Dual Role port), DRP can be used as DFP or UFP. When DPR is connected to UFP, DRP is converted to DFP. When DRP is connected to DFP, DRP is converted to UFP. The two DRPs are connected together, at which point either one is DFP and the other is UFP.
The CC pin of the DFP has a pull-up resistor Rp, and the UFP has a pull-down resistor Rd. When not connected, DFP's VBUS is outputless.
After the connection, the CC pin is connected, and the CC pin of the DFP detects the pull-down resistor Rd of the UFP, indicating that the connection is on, and the DFP is turned on.
Vbus power switch, output power to UFP. And which CC pin (CC1, CC2) detects the pull-down resistor to determine the interface inserted
Direction, by the way, switch RX/TX.
The resistance Rd=5.1k, the resistance Rp is an indeterminate value. According to the previous figure, there are several power supply modes for the USB Type-C. What is the difference? By the value of Rp, the value of Rp is different, the voltage detected by the CC pin is different, and then the power supply mode of the DFP terminal is controlled.
It should be noted that the above picture shows two CCs. In fact, there is only one cc line in the cable without the chip.
The cable containing the chip is not two cc lines, but a cc, a Vconn, used to power the chip in the cable (3.3V or 5V).
At this time, there is no pull-down resistor Rd on the cc terminal, but a pull-down resistor Ra, 800-1200 ohms.