Taking charging as an example, although USB type-c cables natively support a voltage of 20V, the supported currents differ between 3A and 5A. Similarly, the video transmission capability of the USB type-C cable is also an optional option.

I have roughly calculated that there are 13 types of USB type-c cables that are matched according to different functional levels. Among them, cables that only support 3A current but do not support data transmission and video output have the lowest cost, which can be understood as the "beggar version". Cables that support lightning have the highest specification and the most expensive price, and they are also the "emperor" among all USB type-c cables. According to the data in the table above, cables from C to M specifications all have a common feature, which is the need for a chip called "E-Marker". So what exactly is an E-Marker?

The level depends entirely on the E-Marker. USB type-c should be the most chaotic cable in history. In order to standardize their functionality and electrical performance, USB-IF has set a hardware threshold: 1. To support 5A high current; 2. Want to support USB 3.0 or higher transmission speed; 3. To support video output function, E-Marker chip support is required.

The full name of E-Marker is "Electrically Marked Cable", which can be understood as the electronic identity tag of a USB type-c cable. Through this chip, various properties of the cable can be read, including power transmission capacity, data transmission capacity, video transmission capacity, and ID information. Based on this, the output end (such as a charging head or laptop) can adjust the matching voltage/current or audio/video signal according to the device connected to the output end (such as a mobile phone or monitor).

The reason why the A and B cables in Table 2 do not require E-Markers is because they only need to pass 3A current, without considering video output capacity, and the USB 2.0 transmission speed does not have special requirements for the cables. And the C~M specifications cannot be separated from at least one of 1-3, so they all need to be paired with E-Marker chips for input/output device recognition.

It should be noted that the E-Marker chip itself also has different grades. Some E-Marker chips that only support video output, some only support USB 3.1 Gen1 or USB 3.1 Gen2, and some only support 5A current transmission, all of which belong to the lower end. The mid to high-end E-Marker chips have higher integration and can support any 2 or all functions in 1-3, while cables that support all special functions can also be referred to as "fully functional".

In the online cable sales details interface, the various functions and parameter information it supports are usually indicated. However, as mentioned earlier, there are 5Gbps, 10Gbps, 20Gbps, and 40Gbps data transmission speeds, and video output is also supported 4K@60Hz And double 4K@60Hz or 8K@60Hz (Thunderbolt), therefore, fully functional USB type-C cables also have strengths and weaknesses, and the higher the specification, the more expensive the price naturally becomes.

How to look at the E-Marker chip? Although there are two interfaces before and after the USB type-c cable, generally only one interface needs to be embedded with the E-Marker chip, there are also very few cables that are equipped with two E-Marker chips on both interfaces. The advantage of dual chips is that it can increase the success rate of the charger reading the chip, ensuring stable high-power transmission, and better performance when the cable length reaches 2 meters or more.

Belkin Thunderbolt 3 cable, this drawing is from the charging head network

The future development direction of E-Marker chips is towards smaller packaging, as its size increases the complexity and cost of the cable plug part.

The E-Marker chip packaging size of this cable is slightly larger, and this image is from the charging head network

For a long time in the past, E-Marker chips needed to be introduced. The good news is that mainland production of E-Marker chips is on the rise and being used in more brands of USB type-c cables. Among them, representatives include HUSB330 and HUSB332 under Hynetek, as well as UDP300 under Weihai Youwei Technology. They have all passed the USB-IF association certification and support up to 20V/5A power transmission. HUSB332 also supports lightning 3 40Gbps high-speed data communication.

Huinengtai HUSB330 E-Marker chip, this image is from the charging head network

According to the E-Marker chip model, we can search for detailed information about it online. With the release of the 11th generation Core processor, it represents the official commercialization of the USB4 standard. As early as mid October 2020, Yichang Semiconductor launched the first mainland and fifth global E-Marker chip CPS8821 that passed USB-IF USB4 certification, marking a milestone in the popularization and development of USB4 technology. With the acceleration of the localization process of E-Marker chips, the price of mid to high-end USB type-c cables will also further decrease.

It should be noted that the E-Marker chip is only one of the factors determining the functionality and performance of the USB type-c cable. To support higher transmission speeds and video output capabilities, better internal materials for the cable need to be paired. Therefore, many built-in E-Markers in cables that support 10Gbps are used on low-end cables that only support USB 2.0 and 5A charging. We will elaborate on the instructions for cable materials in subsequent chapters.

How to test the performance of E-Marker? Generally, we cannot see its functionality through the appearance of USB type-c cables, and many online stores lack parameter information for cables on sale. How can we quickly identify the actual performance of a cable without dismantling it?

The testing tool series brand POWER-Z under ChargerLAB can achieve testing and analysis of USB type-c cables. Taking POWER-Z KT001 as an example, this product can be powered by a straight in charger or a micro USB interface at the top, triggered by a quick charge through a dial, and switched to the "E-Mark Info Reader" mode. After that, any USB type-c cable can be inserted into the USB type-c interface at the bottom to read the information recorded by the E-Mark chip through the screen. If there is no E-Marker chip inside the cable, the relevant information of the cable will not be displayed on the POWER-Z KT001 screen after inserting the cable.

The POWER-Z KT001 I have in hand was launched earlier, and there is no definition for the data part of lightning cables (up to 10Gbps can be recognized). However, the latest POWER-Z testers that have been launched can already correctly read the 40Gbps performance information of lightning cables. If you are a technical controller or want to test the level of USB type-C cables at home and whether you have been deceived by the merchant, you can consider buying a POWER-Z tester to try it out yourself.

Source: Computer enthusiasts