Since its inception, USB type-c/PD has gained widespread recognition from global customers. In order to better help cable circle friends understand the latest popular technology, we have collected common questions raised on public platforms and consulted with cable predecessors to provide unified answers in the future:

Summary of Common Questions: What is USB 3.1? Actually, just like USB 2.0 and USB 3.0, it is just a type of USB transmission standard. Different transmission standards correspond to different transmission speeds. Currently, the transmission speed of USB 3.1 is higher than that of USB 3.0 and USB 2.0. The higher transmission speed of USB 2.0 can reach 480Mbit/s, USB 3.0 can reach 5Gbit/s, USB 3.1 can reach 10Gbit/s, USB 3.0 has a transmission speed 10 times that of USB 2.0, and USB 3.1 has a transmission speed 2 times faster than USB 3.0.

At present, there is still a distinction between true and false USB 3.1. A fake USB 3.1 is called USB 3.1 Gen1, with a transmission speed of 5Gbit/s, but USB 3.0 has just been upgraded. The true USB 3.1 is called USB 3.1 Gen2, with a transmission speed of up to 10Gbit/s.

According to different transmission speeds, USB 2.0 is also known as USB High Speed, abbreviated as HS; USB 3.0 is called USB Super Speed, abbreviated as SS; USB 3.1 is called USB Super Speed Plus, abbreviated as SS

What is USB type-C? It is actually just an interface form of USB. The interface forms of USB can be divided into USB type-a, USB type-b, and USB type-c. There are also two different interface forms for USB type-a and USB type-b, namely USB mini-A (B) and USB Micro-A (B).

What is USB PD? It is actually a charging standard for USB, and USB PD is the fast charging standard for USB. At present, there is no unified standard for fast charging technology on the Android platform. Major manufacturers such as Quick Charge, VOOC flash charging, SuperCharge, Dash charge, and turbo fast charging have independently developed fast charging technologies. However, to achieve fast charging, special wires provided by corresponding manufacturers need to be used, which does have many inconveniences for consumers. To end this chaos, Google may create some rules on the Android system to change the situation.

What is the difference between USB Power Transmission (USB PD) and USB type-c? USB PD is a protocol specification that supports both up to 100W power transmission and data communication in one cable

USB type-c is a new specification for directionless forward and backward USB connectors that supports multiple new standards, including USB 3.1 (Gen1 and Gen 2), Display Port, HDMI, and USB PD

The USB type-c port can support up to 5V3A power transmission by default. If a USB PD is implemented in the USB type-c port, it can support up to 100W power transmission

Therefore, having a USB type-c port does not mean it supports USB PD.USB type-c connectors are mandatory for the USB 3.1 Gen 1 or Gen 2 specifications? Is USB type-c equivalent to USB 3.0/3.1.

At present, we can use traditional type-a or type-b connectors to support Gen 1 and Gen 2 specifications. The USB type-c specification is a new interface certification specification released by the USB Developer Forum (USB-IF), which can support up to 100W power transmission and unidirectional forward and backward insertion. All USB 3.1 Gen 1 or Gen 2 specification products can use the USB type-c interface

Therefore, our answer is that the USB type-c specification is independent of the USB 3.1 Gen1 or Gen 2 specification. What are DFP, DRP, and UFP, respectively? DFP (Downstream Facing Port) is a USB Type-C port installed on the host or hub to connect to the device, and UFP (Upstream Facing Port) is a USB type-c port connected to the host or hub, DFP, on the device or hub. Dual Role Port (DRP) is a definition of a dual role power port that can serve as a Source or Sink role on a USB type-c port. The DRP mentioned above is different from a dual role power interface, which refers to a power port that can serve as a Power Source (provider) and Sink (consumer). For example, the USB type-c port on a laptop supports DRP (i.e. type-c dual role power interface), It can be used as a Power Source (when connecting a removable disk or phone) or as a Sink (when connecting a display screen or power adapter).

What is the configuration channel (CC) line? What is the maximum speed of the CC bus?

CC bus is a data line used for USB-PD communication between ports and EMCA

There are two pins CC1 and CC2 on the USB type-c socket, one of which is recognized as a CC line based on the direction of the plug connected to the USB type-c

For USB type-c plugs, the CC cable is fixed

The CC line can operate the following functions:

Detect the direction of the USB type-C plug to establish USB data bus routing

Detect USB port connection from DFP to UFP

Establish the roles of DFP and UFP between ports

Find and configure VBUS

Configure VCONN

Find and configure optional backup and attachment modes

The bit rate of CC line varies from 270Kbps to 300 Kbps, with a rated value of 300Kbps

What is the difference between Cypress USB-PD2.0 and Qualcomm QC fast charging?

USB-PD 2.0 is a protocol developed by USB-IF that provides a power supply mechanism of up to 100 W (20V, 5A) between USB devices. It also supports both USB and non USB data signals on the USB Type-C port, allowing for flexible negotiation of power supply direction between the host and peripheral devices

Qualcomm Quick Charge is a Qualcomm exclusive charging protocol that uses a custom charger that supports the Qualcomm Quick Charge protocol to charge devices that also support the protocol. Quick Charge 2.0 can transmit up to 60 W of power, but unlike USB-PD, Quick Charge 2.0 cannot support both power and data transmission, nor does it support flexible selection of power supply direction during charging.

How many power transmission objects (PDOs) can the Cypress USB-PD controller support at most? What are the supported power configuration files?

Cypress USB-PD supports up to 7 types of PDO for both pull-current and pull-current applications

The USB-PD specification does not require which power configuration files the application device needs to support. The PDO for pulling and pouring current depends on the application design. Section A.1 of the USB type-c specification defines standardized combinations of voltage and different current ranges. It should be noted that the power configuration file defined in Section A.1 is only recommended and not mandatory, but at least one PDO that can support 5V pulling current is required

Can I only use the USB and standard 5V VBUS functions of the USB type-c port?

Yes, you can use a USB type-c port that only has USB functionality and supports standard 5-V VBUS; Host side: The host type-c port is USB 2.0

What are the limits for existing twisted pair materials or coaxial lines that can meet USB 3.1 Gen1 (5G) requirements? The following figure shows the structure reference of USB3.1 twisted wire and coaxial wire respectively!

The following figures show the lengths of the reference type-c series!

Explain how many meters the high-frequency line crosses, and what exactly does G refer to? Thank you!

Performance indicators for wire transmission

Low frequency: below 12KHz, the main parameter is capacitance, and the characteristic capacitance is unbalanced

High frequency: Above 12KHz, parameters include attenuation, crosstalk, delay, delay difference, characteristic impedance, transmission speed, etc

Common high-frequency related units and converted dB decibels are mainly used to describe the unit of sound, such as Hz Hz for attenuation and crosstalk, the unit of frequency Ω ohm, the unit of impedance Ps, ns, picosecond, nanosecond, and the unit of time Conversion of units: (decimal) T Tai (1012) G Ji (109) M Mega (106) K Kilo (103) ★ International unit m Milli (10-3) μ Micro (10-6) n Nano (10-9) P Pi (10-12) F Fei (10-15)

How much G does a high-frequency wire pass a few meters? This mainly refers to comparing the test data of the actual test wire according to the requirements of the test specifications. If it meets the parameters in the test specifications, it means passing; if it does not meet the requirements of the test specifications, it means not passing! (Use the following example to illustrate the data)

Source: Cable industry