What Is The Difference between 3A Cable and 5A Cable?

2023-03-16 What is the difference between 3A cable and 5A cable?

With the iteration of smartphone charging technology, the charging power has developed from 5W to 240W now, the interface specification, wire and charger obviously look similar on the surface, why is it so far apart? Especially the wire specifications, apparently all USB-C cable, the price difference is several times, with the 100W charger when the power can not reach the maximum output, how to charge or so slow?

In fact, the standard USB-C cable also exists in the charging "performance grading" system, the most common is the 3A cable, 5A cable two specifications, now, ZONSAN from the charging cable to introduce these two types of data cable why will affect the system charging power.

Cable form

USB-C interface is currently the most common fast charging interface on the market, and USB-C cable form there are many kinds, mainly USB-C to USB-C, USB-A to USB-C, USB-C to Lightning three types, because USB-C to Lightning is not a universal wire, this article does not explore in detail, mainly for USB -C to USB-C and USB-A to USB-C.

E-Marker Chip



According to the USB specification, there are three players in the USB PD / USB-C point-to-point connection system, the powered device (Source), the powered device (Sink), and the cable.

In each connection, the devices will "negotiate" through the cable to know whether the other end of the cable is a cell phone or charger or computer, to determine whether the other side is a powered or powered device, to communicate power supply specifications / powered specifications, data transfer rate specifications and other key information.

The USB-C cable is an important bridge for information communication and power transmission, and the "E-Marker" chip can be added to the terminal to participate in the "information negotiation" as a third party.

The E-Marker chip is "optional", the current of the wire without E-Marker chip is limited to 3A for safety reasons, to avoid the safety problem of high resistance and high current overheating; while the wire with 3A E-Marker chip, the maximum current transmission of the whole fast charging system is also 3A; the wire with 5A E-Marker chip, the whole fast charging system is also 3A. The maximum current transmission of the whole fast charging system can only reach 5A with the wire that uses 5A E-Marker chip.

The maximum power transmission specifications of the data cable are mainly divided into two types, 60W / 100W, according to the current division is 3A wire / 5A wire, except for the lightning data cable, the power transmission performance of other data cables and data transmission performance is not directly related. If you want to get higher than 60W (3A) fast charging performance, a 100W (5A) cable is necessary to read the product description when buying, buy the wrong power will be limited can not exceed 60W (3A) use.

3A cable



3A cable is one of the most widely used wires on the market, the appearance of the wire, the terminal is not clearly marked. From the literal meaning of "3A" can be understood, its maximum transmission current value of 3A, based on the USB PD3.0 maximum voltage of 20V for calculation, its maximum withstand fast charging power of 60W.

The 3A cable generally does not include the E-Marker chip, and is designed and manufactured according to the power specifications in terms of contact gold plating, core thickness, and cost control.

60W fast charging power for ordinary cell phones, tablets, Switch game consoles, ultrabooks, are sufficient, the price is relatively low, many chargers below 60W are standard with 3A cable.

5A cable



5A cable compared to 3A cable, the current transmission specifications are nearly doubled, and the requirements for all aspects of the wire are more stringent. In terms of appearance, 5A cables are generally clearly marked with the word "5A" on the outer packaging and at the end of the terminal head net for easy identification by users. From the literal meaning of "5A" can be understood, its maximum transmission current value of 5A, based on the USB PD3.0 maximum voltage of 20V for calculation, its maximum withstand fast charging power of 100W.



The 5A cable must have a built-in 5A E-Marker chip, and during the "information negotiation" process between the power supply device and the receiving device, the key parameter that the cable supports 5A is obtained, so that the whole fast charging system can break through the 3A current transmission limit. 5A cable production design and manufacturing processes are more complex, with thicker gold-plated connectors, wider shrapnel, thicker wire The design and manufacturing process of 5A cables are more complex, with thicker gold-plated connectors, wider shrapnel, thicker cores, and usually cotton threads and lubricating powders are added to enhance flexibility and prevent the cable from being too hard.



100W fast charging power can be used for flagship fast-charging cell phones, high-performance notebooks, high-powered rechargeable batteries and other more demanding devices, the price, manufacturers are more willing to spend on the 5A wire design, anti-abrasion and anti-pull design to enhance product durability, 5A wire prices also rose.



As early as 2016, ZONSAN has conducted electrical performance tests on a variety of wires, in the pressure drop internal resistance test link can be seen, two 5A cable resistance as low as 0.06Ω, much lower than other ordinary cables, its voltage drop through the high current is lower, less energy loss, and will not easily heat up.