The relationship between type-C and fast charging

Does fast charging conflict with fast data transmission? Does the fast charging line only charge but not transmit data? Can fast charging and fast transmission be realized at the same time? What brands and models are recommended? What is the principle and standard of fast charging? Is it related to the charging head or the cable itself? At present, there are probably so many problems in the communication of cable engineering R & D group. Today, let's talk about the relationship between type-C and fast charging


When it comes to type-C and fast charging, we have to mention microusb and fast charging first. In the case of mobile phone suck, it is a good solution to increase the charging speed. We learned physics, and the key to improve the charging speed is to increase the power of charging. Power (W) = current x voltage. The charger first reduces the mains power from 220 V to 5 V and outputs it to the micro USB interface of the mobile phone, and then reduces the internal circuit of the mobile phone to about 4.3 V to charge the battery. There are two steps to reduce blood pressure.


Before the charger output voltage is 5V, we think about how to improve the current; However, when it reaches 5V 2a, the bottleneck will come: if the current increases again, a large number of micro USB interfaces and data cables will be unable to withstand. At present, the universal micro USB interface and our USB data cable can only ensure safe and efficient transmission under 2A current. If the current exceeds 2a, the hardware can't stand it. What should we do? That's when type-C came along. The number of contacts of type-C interface is several times that of micro USB interface, which greatly increases the current intensity it can withstand; At the same time, type-C adds the step of mutual identification, which can define itself as charger or receiving device. In other words, USB type-C naturally supports fast charging. Under the same current, the loss of USB type-C will be smaller, and it can support bidirectional charging. Although type-C naturally supports fast charging, it doesn't mean that the use of type-C necessarily supports fast charging, and the fast charging charger doesn't necessarily use the type-C interface. For cost and fever reasons, some manufacturers only use type-C, but do not support fast charging. Since 2018, mobile phone fast charging has gradually increased from 18W to 40W or even 65W. This year, the mobile phone industry is expected to enter the era of 240W fast charging; New usb-c specification: support up to 240W power, need to upgrade cable


Mobile phone charging is based on P (power) = u (voltage) × I (current), so the way to increase the power is to increase the voltage or current and both. High pass qc1.0 is to improve the charging power by increasing the current. However, charging mobile phones is not only about the charging head, but also our old line. In 2014, when Qualcomm wanted to continue to increase the current along the direction of qc1.0 to improve the charging power, it found that it couldn't go any further. At this time, although the type-C data cable has been released, it is far from popular. We all use the microusb 2.0 data cable, and its internal structure leads to its limited current carrying capacity. 2A has basically come to an end. Based on this, USB if released the charging standard of USB power delivery (USB PD) based on the type-C interface in USB 3.1, It can provide up to 100W (20V / 5A) charging power, aiming at unifying the charging standard of portable mobile devices. Besides USB if, Google also said that Android must support USB PD. What is usb-pd technology; Discussion on USB pd3.1 fast charging specification


In 2017, USB pd3.0 is compatible with Qualcomm qc4.0/3.0, oppo vooc, Huawei FCP / SCP, etc., and covers high voltage, low current and low voltage, high current. The voltage output range is 3.0v-20v, the voltage regulation range is 20mV, and the current range is 1.5A, 2a, 3a, 5A.

In 2017, Qualcomm released qc4.0 +, which improved dual power management IC, intelligent heat balance, advanced security features, etc. At the same time, it is compatible with USB PD 3.0 (PPS) protocol and downward compatible with pd2.0, qc3.0, qc2.0, etc. After the pd3.0 protocol came out, it means that a set of standards has been formulated.

Usb-pd protocol and other manufacturers' fast charging protocol are not the same relationship, but the relationship between inclusion and inclusion. In the PPS (fast charging technical specification) released by usb-if, usb-pd 3.0 protocol has included Qualcomm QC 3.0 and 4.0, Huawei SCP and FCP, MTK pe3.0 and pe2.0, and oppo vooc; PD charging will unify fast charging

Even if you use a fast charging mobile phone and a fast charging head, if you use a non fast charging data line, there is no fast charging effect. The material and quantity of the data line's core wire will affect the maximum current that the data line passes through, thus affecting the charging power. Therefore, when selecting a data line, you should choose a data line with a pure copper core material and a large number of core wires, Generally, the design of the fast charging data line is 5C wire, and the braided structure is used to protect the internal wire core. Generally, the red represents the design of the current positive pole to ensure the current transmission. At present, the thickest data line in the industry has 19AWG conductor, and it is difficult to weld beyond this AWG number, and the pad is easy to fall off. White and green are the positive and negative data lines to ensure the data transmission, The blue design is the CC interface, which is responsible for the support of PD fast charging. Of course, in order to reflect the difference from the ordinary data line, there are often ground wire design and the application of Kevlar wire to increase the service life, which depends on the price range given by the customer. What causes the voltage drop? The line resistance plays a decisive role in the voltage drop

With the rapid charging of USB PD, it is becoming a fast charging solution for almost all mobile devices, such as smart phones, laptops, pads, cameras, game consoles, UAVs, etc., and becoming a real 'universal charger'. Connectors and data cables supporting fast charging will gain more market share in the online cable industry. We will wait and see.