Connecting a monitor via USB Type C
USB 3.1 Type-C pinout
The “striped color” here shows the contacts of a bare wire.
A strange solution was to mark wires D and D- not as in USB 2.0, but vice versa: D white, D- green.
The gray outline marks the wires whose color, according to Wikipedia, is not regulated by the standard. The author did not find any indication of the colors of the wires in the official documentation at all.
Wiring Type-C connectors
Typical USB-C male-to-male cable diagram
Power / Charge Technology USB PD Rev.2 (USB Power Delivery)
The USB-C cable does not have such concepts as “connector-A” or “connector-B”. the connectors are now the same in all cases.
Device roles are denoted with new terms:
DFP. active, power supply device (like a USB-A port)
UFP. passive, receiving device (like a USB-B port)
DRP. “two-faced” device dynamically changing its status.
In addition, the charger is called Power Provider, the rechargeable is called Power Consumer.
The distribution of roles is carried out by setting a certain potential on the CC contact using one or another resistor:
▶ The active device (DFP) is detected by the resistor between CC and Vbus pins.
The resistor value tells the consumer what current he can count on:
56 ± 20% kOhm. 500 or 900 mA
22 ± 5% kOhm. 1.5 A
10 ± 5% kOhm. 3 A
▲ Adapters from USB 2.0 (3.0) to USB-C, used to connect new smartphones to old PCs or storage devices, are soldered according to the DFP scheme, that is, they show themselves to the smartphone as an active device
▶ Passive device (UFP) is detected by the resistor between CC and GND.
Resistor rating: 5.1K ohm
▲ Adapters from USB-C to USB-OTG are soldered exactly according to the UFP scheme, that is, they SIMulate a consuming device.
⚠ USB PD Rev2 technology, in which the charge current and voltage are matched on the CC pin, should not be confused with the Quick Charge (QC) technology, where only the charge voltage is matched on the D- and D pins. USB PD Rev2 is only supported in USB 3.1.
QC is supported without reference to the port version.
Universal adapter option
Our reader Kirill shared a diagram of an interesting adapter SIMilar to the previous one ▲. The key difference is that the micro-USB socket does not use the ID pin. and both resistors (both DFP and UFP) are permanently connected.
The device to which this adapter is connected via Type-C determines its role by the presence or absence of voltage at the Vbus pin. If you first connect the charger to the adapter via the micro-USB socket, and then connect the adapter to the smartphone, the smartphone port detects the charge voltage and switches the smartphone to consumption mode. If you just connect the adapter, then the smartphone enters the OTG mode and supplies the voltage itself.
The adapter was tested on a smartphone Samsung Galaxy S8.
The micro-USB 2.0 to USB type-C adapter is used to connect a gadget with a Type-C socket to a standard USB 2.0 data cable for charging and synchronizing with a PC. The adapter has a 56 kOhm resistor between the CC and Vbus pins.
This resistor, as it were, says to the smartphone: “You have connected an active device. charge. I will not give more than 0.9 amperes “.
That is, even from a powerful charger (say, 3 amperes) through such an adapter, we will not take more than 0.9 amperes. So that the smartphone does not hesitate and take 3 amperes, you need to replace the 10 kΩ resistor
USB-C to USB-AF adapter
To connect USB peripherals to a device with a USB-C port, a 5.1 kΩ resistor is required in the adapter between the CC and GND pins.
This resistor tells the smartphone: “A passive device is connected to you. Give me food “.
Consider the OTG type-C adapter diagram using the example of Type-C USB 3.1 To USB 3.0 OTG Adapter. This is an adapter for connecting USB 3.0 (2.0) peripherals to a PC or to a Type-C smartphone.
The colors of the Data, TX and RX wires in this model are slightly different from the canonical ones, please pay attention to this!
Another important detail. in all adapters of the USBtype-C — type-C or USBtype-C — USB3.0 type (not necessarily OTG!), A capacitor is required between the Vbus and Gnd pins to protect the connector pins from sparks when connected. For example, adapters to USB 3.0 require a capacitor rating of 10nF ± 20% × 30V. USB 3.1 adapters require a larger capacitor, while USB 2.0 adapters do not require a capacitor at all. Read more in the English-language article “VBUS Bypass Capacitor”.
Pinout of the Type-C to USB 3.0 OTG adapter board from different sides
Analog audio via Type-C
The standard provides for the ability to transmit analog sound through a digital port. This feature is implemented in smartphones HTC U series, HTC 10 Evo, Xiaomi Mi, LeTV. The author will be grateful if the reader will add to this list.
The mode is called “Audio Adapter Accessory Mode”. For details, see the article “Analog Audio over USB-C”.
To work in this mode, analog headsets with a Type-C plug are used. Adapters are provided for connecting a classic headset with a jack plug.
Analog audio is transmitted via Data-, Data, SBU1 and SBU2 channels. The smartphone goes into this mode if the resistance of the headset or adapter between contacts A1-A5 and B1-B5 is less than 0.8. 1.2 kOhm. Instead of a resistor, I just saw a jumper.
Universal USB-micro-USB-C adapter with OTG support
Our reader Sergey sent a diagram of a universal adapter micro-USB-BF to USB type-C (Type 51125 Z22). through it you can connect both a Data cable and an OTG USB 2.0 cable. Depending on the cable, the smartphone either charges or works with peripherals.
Ideally, instead of 55 kOhm, it would be worth using 51 (as in a SIMilar adapter from Huawei) so that the canonical 56 kOhm is obtained in the Vcc-CC circuit. But the specification doesn’t require that kind of precision. Resistance rating Vcc-CC is allowed in the range 45. 67 kOhm.
USB 3.1 Type-C. Short, clear, detailed
power and charge
Advantages of the USB 3.1 port:
Advantages of the Type-C connector:
Now it is guaranteed that you can connect the USB cable to the device the first time.
⚠ Distinguish between the concepts of “port” and “connector”. The Type-C connector (socket) can be soldered even to an old phone (instead of micro-USB), but the port will remain the old USB 2.0. this will not add charging and data transfer speeds. Of the convenience, only the symmetry and reliability of the connector will appear.
⚠ Thus, the presence of Type-C does not mean anything yet. Smartphone models are on sale with a new connector, but with an old port. The advantages listed in this article do not apply to such smartphones.
The contacts of the connectors in the diagrams are shown from the outer (working) side, unless otherwise specified.
The port contains 24 pins (12 pins on each side). The “upper” ruler is numbered A1… A12, the “bottom” one. B1… B12. For the most part, the lines are identical to each other, which makes this port indifferent to the orientation of the plug. The contacts of each line can be divided into 6 groups: USB 2.0. USB 3.1. Food. Land. Matching channel and Additional channel. Now let’s take a closer look.
Actually, USB 3.1. High-speed data lines: TX, TX-, RX, RX- (pins 2, 3, 10, 11). Speed up to 10 Gb / s. In the cable, these pairs are crossed, and what is RX for one device is presented as TX to another. And vice versa. By special order, these pairs can be retrained for other tasks, for example, for video transmission.
Good old USB 2.0. Low speed data lines: D / D- (pins 6, 7). This rarity was included in the port for the sake of compatibility with old low-speed devices up to 480 Mb / s.
Power supply plus. Vbus (pins 4, 9). The standard voltage is 5 volts. The current is set depending on the needs of the periphery: 0.5A; 0.9A; 1.5A; 3A. In general, the specification of the port implies a transmitted power of up to 100W, and “in case of war” the port is able to power a monitor or charge a laptop with a voltage of 20V!
GND. “Ground”. coil (pins 1, 12). Minus everything and everything.
The matching channel (or configuring). SS (pin 5). This is the main feature of USB type-C! Thanks to this channel, the system can determine:
Additional channel. SBU (pin 8). The additional channel is usually not used and is provided only for some exotic cases. For example, when transmitting video via cable, an audio channel is sent via SBU.
Compatibility. Difficulties of the “transition” period
If we talk about the compatibility of USB Type-C with devices equipped with USB ports of the previous generation, then it is not possible to connect them directly due to the fundamental differences in the design of the connectors. To do this, you need to use adapters. Their assortment promises to be very wide. Of course, it’s not just about converting USB Type-C to other USB types. Display adapters for displays with traditional DisplayPort, HDMI, DVI and VGA ports will also be available.
Apple SIMultaneously with the announcement of the new MacBook offered several adapter options. Single USB Type-C to USB Type-A rated 19.
Given the presence of only one USB Type-C, the owner of a MacBook probably cannot do without a universal, more functional converter. Apple introduced two of these adapters. One on the output has a pass-through port USB Type-C, VGA and USB Type-A, the second option is equipped with HDMI instead of VGA. The cost of such boxes is 79. A 29 W power supply with native USB Type-C hung at 49.
Google for the new Chromebook Pixel system offers single USB Type-C to Type-A (plug / socket) adapters at the price of 13, for a converter to DisplayPort and HDMI you will have to pay 40. 60W PSU is priced at 60.
Traditionally, one should not expect humane price tags for additional accessories from equipment manufacturers. Adapter manufacturers are anticipating the demand for their new products. Belkin is already ready to ship kilometers of conductors, but their cost is also not low (20-30). The company also announced, but has yet to provide a USB Type-C to Gigabit Ethernet adapter. The cost has not yet been announced, there is information only that it will be available in early summer. It’s funny, but it seems that up to this point, to connect to a wired network, you will need to use two adapters at once. It is possible that someone will be quicker than Belkin by offering an appropriate adapter earlier.
It will be possible to speak about a noticeable price reduction only after much less well-known companies from the “Celestial Empire” are closely engaged in accessories with USB Type-C. Considering what prospects open up, we believe that they will not be.
USB Type-C: A universal connector for everything. Energy transfer. Unit for 100 W
Another important feature that USB Type-C brings is the ability to transfer power up to 100W. This is enough not only for powering / charging mobile devices, but also for the trouble-free operation of laptops, monitors or, for example, “large” external 3.5 ”drives.
In the original development of the USB bus, power transmission was a secondary function. The USB 1.0 port provided just 0.75W (0.15A, 5V). Enough for mouse / keyboard operation, but nothing more. For USB 2.0, the nominal current was increased to 0.5 A, which made it possible to get already 2.5 W. This was often enough to power, for example, external 2.5 ”hard drives. For USB 3.0, a current of 0.9 A is nominally provided, which, with a constant supply voltage of 5V, already guarantees a power of 4.5 W. Special reinforced connectors on motherboards or laptops were capable of delivering up to 1.5A to speed up charging of connected mobile devices, but that’s still 7.5W. Against the background of these numbers, the ability to transmit 100 watts looks like something fantastic. However, for the USB Type-C port to be filled with the necessary power, support for the USB Power Delivery 2.0 (USB PD) specification is required. If there is none, the USB Type-C port will be able to supply 7.5 W (1.5 A, 5 V) or 15 W (3A, 5 V) to the mountain, depending on the configuration.
In order to streamline the power capabilities of the USB PD ports, a system of power profiles has been developed that allow for possible combinations of voltages and currents. Compliance with Profile 1 guarantees the ability to transfer 10 W of energy, Profile 2. 18 W, Profile 3. 36 W, Profile 4. 60 W, Profile 5. 100 W. The port corresponding to the higher profile maintains all the states of the previous downstream. 5V, 12V and 20V are chosen as reference voltages. The use of 5V is essential for compatibility with the vast array of USB peripherals available. 12V is the standard supply voltage for various system components. 20V is proposed taking into account that external power supplies for 19-20V are used to charge the batteries of most laptops.
Of course, it’s good when the device is equipped with USB Type-C supporting the maximum USB PD energy profile. It is this connector that allows you to transfer up to 100 watts of energy. It is obvious that ports with SIMilar potential may appear on some powerful laptops, special docking stations or motherboards, where separate phases of the internal power supply will be allocated for the needs of USB Type-C. The point is that the required power must be somehow generated and brought to the USB Type-C contacts. And to transfer energy of such power, active cables will be required.
It is important to understand here that not every port of the new format will be able to provide the declared power of 100 watts. There is a potential for this, but this issue must necessarily be resolved by the manufacturer at the circuitry level. Also, do not entertain the illusion that the above 100 W can be obtained, say, from a power supply the size of a matchbox, and now you can power your gaming laptop and a 27-inch monitor connected to it with a smartphone charge. Nevertheless, the law of conservation of energy continues to work, and therefore an external 100 W PSU with a USB Type-C port will still be the same weighty bar as before. In general, the very possibility of transmitting energy of such power using a universal compact connector is, of course, a plus. At the very least, a great opportunity to get rid of the inconsistency of the original power connectors, which laptop manufacturers often sin.
Another useful feature of USB Type-C is the ability to change the direction of power transmission. If the circuitry of the devices allows, the consumer can, for example, temporarily become source of charge. over, for the reverse energy exchange, you do not even need to reconnect the connectors.
Design. Convenient connection
The USB Type-C connector is slightly larger than the usual USB 2.0 Micro-B, but noticeably more compact than the dual USB 3.0 Micro-B, not to mention the classic USB Type-A.
The dimensions of the connector (8.34 × 2.56 mm) make it easy to use for devices of any class, including smartphones / tablets with a minimum reasonable thickness of the case.
Structurally, the connector has an oval shape. Signal and power outputs are located on a plastic stand in the central part. The USB Type-C pin group includes 24 pins. This is much more than the previous generation USB connectors. Only 4 pins were allocated for the needs of USB 1.0 / 2.0, and USB 3.0 connectors have 9 pins.
The first obvious benefit of USB Type-C is the symmetrical connector, so you don’t have to worry about which side to connect the plug to the outlet. The age-old problem of devices with USB connectors of any format is now finally solved. In this case, the solution to the problem is achieved by not trivial duplication of all contact groups. It uses certain auto-negotiation and switching logic.
Another nice thing is that identical connectors are located on both sides of the interface cable. Therefore, using USB Type-C, you do not need to choose which side of the conductor to connect the master and slave devices.
The outer shell of the connector does not have any holes or cutouts. Internal side latches are used to secure it in the connector. The plug must be sufficiently secure in the connector. There should not be any backlashes SIMilar to those seen in USB 3.0 Micro-B.
Many are probably worried about the physical reliability of the new connector. According to the declared characteristics, the mechanical life of the USB Type-C connector is about 10,000 connections. The same indicator is typical for the USB 2.0 Micro-B port.
Separately, we note that USB Type-C is not a data transfer interface. This is a type of connector that allows you to link together various signal and power lines. As you can see, the connector is elegant from an engineering point of view, and most importantly, it should be easy to use.
The first version of the Universal Serial Bus (USB) was introduced in 1995. It is USB that has become the most successful interface in the history of computing systems. Tens of billions of devices communicate with each other via USB, so the importance of this data transmission channel can hardly be overestimated. It seems that with the advent of the USB Type-C connector, our understanding of the possibilities and role of the universal bus may radically change. Before talking about the prospects, let’s see what the new format universal connector offers.
The advantages and disadvantages of the new format interface connector have been discussed on the net for some time. The USB Type-C specification was finally approved back in the late summer of last year, but the topic of the universal connector has attracted active interest after the recent announcement of the Apple MacBook laptop, as well as the new version of Chromebook Pixel equipped with USB Type-C.
USB Type-C devices. Someone must be first
Nominally, the first device equipped with a USB Type-C port was the Nokia N1 tablet. At least, it was this device that became a harbinger of the fact that the ports of the new format left the development laboratories and “go to the people”.
An interesting device, but, unfortunately, it is still offered in a fairly limited edition. The tablet has a native USB Type-C port, although the USB 2.0 protocol is used for data transfer.
Perhaps the most iconic product that will help drive USB Type-C popularity is the recently unveiled Apple MacBook. The 12-inch laptop is equipped with a single interface connector, so its owners will somehow become pioneers who will adapt to life with USB Type-C.
On the one hand, Apple obviously supported the development of the new standard, moreover, the company’s engineers were directly involved in the development of USB Type-C. On the other hand, the updated versions of the Macbook Air and MacBook Pro did not receive this connector. Does this mean that in the “heavier” category of devices of the manufacturer USB Type-C will not be registered in the coming year? Controversial. After all, surely Apple will not be able to resist updating the line of laptops after the autumn announcement of Intel’s new mobile platform with Skylake processors. Perhaps that’s when the Cupertines will allocate space on the interface panel for USB Type-C.
The situation with tablets and smartphones is even more controversial. Will Apple use USB Type-C instead of Lightning for them? The proprietary connector in terms of capabilities is noticeably inferior to the new universal port, but what about the original peripherals that have accumulated among users of Apple mobile products since 2012? We will find out the answers to these questions with the update or expansion of the iPhone / iPad lines.
Google has unveiled the second generation of stylish Chromebook Pixel laptops. Chrome OS systems are still quite niche solutions, but the quality of Google’s systems captivates, moreover, this time they are at the forefront of devices offering to join USB Type-C. Laptops are equipped with a pair of matching connectors. However, to hedge Chromebook Pixel also have two classic USB 3.0 ports.
In general, Google representatives are very encouraged by the capabilities of the new connector, counting on the appearance of Android mobile devices with a USB Type-C connector in the near future. Uncompromising support for the largest platform holder is a powerful argument for other market players.
Motherboard manufacturers have been slow to add a USB Type-C port to their devices yet. MSI recently introduced the MSI Z97A GAMING 6, which is equipped with this connector with a data transfer rate of up to 10 Gb / s.
ASUS offers an external USB 3.1 controller with a USB Type-C port that can be installed on any board with an empty PCI Express (x4) slot.
Peripheral devices with native USB Type-C are not enough yet. Surely, many manufacturers were in no hurry with the announcement, waiting for the appearance of systems with which it would be possible to use products with USB Type-C. In general, this is a typical situation when implementing the next industry standard.
Immediately after the announcement of the Apple MacBook, LaCie introduced a series of portable external hard drives with USB Type-C.
SanDisk is already offering a USB 3.0 Type-A and USB Type-C flash drive for trial. A SIMilar product is offered by the lesser-known Microdia.
We will surely see a significant expansion of the range of USB Type-C devices soon. The flywheel of change will slowly but surely unwind. Supporting “big” companies can influence the situation and speed up this process.
Data transfer rate. 10 GB / s is not for everyone?
One of the advantages of USB Type-C is the ability to use the USB 3.1 interface for data transfer, which promises an increase in bandwidth up to 10 Gb / s. However, USB Type-C and USB 3.1 are not equivalent terms and are definitely not synonyms. In the USB Type-C format, both USB 3.1 and USB 3.0 and even USB 2.0 can be implemented. An integrated controller determines the support of a particular specification. Of course, USB Type-C ports are more likely to appear on devices that support high data transfer rates, but this is not a dogma.
Let us recall that even with the implementation of USB 3.1 capabilities, differences in the maximum data transfer rate are possible. For USB 3.1 Gen 1 this is 5 Gb / s, USB 3.1 Gen 2 is 10 Gb / s. By the way, the presented Apple Macbook and Chromebook Pixel have USB Type-C ports with a bandwidth of 5 Gb / s. Well, a clear example of the fact that the new interface connector is very variable is the Nokia N1 tablet. It also has a USB Type-C connector, but its capabilities are limited to USB 2.0 with 480 Mb / s bandwidth.
The USB 3.1 Gen 1 designation can be called a marketing gimmick. Nominally, such a port has the same capabilities as USB 3.0. over, for this version of “USB 3.1” the same controllers can be used as for the implementation of the bus of the previous generation. At the initial stage, this technique will most likely be actively used by manufacturers, releasing new devices with USB Type-C for which maximum bandwidth is not required. When proposing a device with a new type of connector, many will want to present it in a favorable light, declaring the presence of not only a new connector, but also support for USB 3.1, even if only conditional.
It is important to understand that nominally, the USB Type-C port can be used for maximum performance connection at speeds up to 10 Gb / s, but in order to get such bandwidth, connected devices must provide it. The presence of USB Type-C is not an indication of the actual speed capabilities of the port. They should be clarified in advance in the specifications of specific products.
Some restrictions also have cables for connecting devices. When using the USB 3.1 interface, for lossless data transfer at speeds up to 10 Gb / s (Gen 2), the cable length with USB Type-C connectors should not exceed 1 meter, for connection at speeds up to 5 Gb / s (Gen 1). 2 meters.
Alternative mode. Not USB single
The USB Type-C port was originally designed as a universal solution. Besides direct USB data transfer, it can also be used in Alternate Mode to implement third party interfaces. This flexibility of USB Type-C was used by the VESA association, introducing the ability to transfer video streaming via DisplayPort Alt Mode.
USB Type-C has four Super Speed USB lines (pairs). If two of them are dedicated to DisplayPort, that’s enough to get a 4K (3840×2160) picture. This does not affect the USB data transfer rate. At its peak, this is still the same 10 Gb / s (for USB 3.1 Gen2). Also, the transmission of the video stream does not in any way affect the energy capacity of the port. Even high-speed 4 lines can be allocated for DisplayPort needs. In this case, modes up to 5K (5120 × 2880) will be available. In this mode, USB 2.0 lines are not involved, so USB Type-C will still be able to transfer data in parallel, albeit at a limited speed.
In the alternative mode, the SBU1 / SBU2 pins are used to transmit the audio stream, which are converted to the AUX / AUX- channels. They are not used for the USB protocol, so there are also no additional functional losses here.
With the DisplayPort interface, the USB Type-C connector can still be connected either way. The required signal matching is provided initially.
Connecting devices using HDMI, DVI and even D-Sub (VGA) is also possible, but this will require separate adapters, however, these must be active adapters, since for DisplayPort Alt Mode, Dual-Mode Display Port (DP) mode is not supported.
The USB Type-C alternate mode can be used for more than just DisplayPort. Perhaps soon we will learn that this port has learned, for example, to transfer data using PCI Express or Ethernet.
The need for a universal compact connector that could be used to transfer data, video-audio streams and electricity has been long overdue. Given the mutual interest of both users and equipment manufacturers, there are all the prerequisites for USB Type-C to “shoot”.
Compact size, SIMplicity and ease of connection, along with ample opportunities promise the connector to repeat the success of its predecessor. The familiar USB port has been upgraded several times, but the time has come for fundamental changes. 10 Gb / s with the possibility of further scalability, power transmission up to 100 W and a picture with a resolution of up to 5K. Not a bad start? Another argument in the USB Type-C piggy bank is an open standard that does not require royalties from manufacturers. There is still a lot of work to be done, but there is a result ahead, for which it is worth walking this path.
Understanding USB Type-C cables. It’s just a trash heap
In 2015, Apple released its first gadget equipped with a new and surprisingly single USB Type-C port. MacBook, which has only one port, caused a flurry of discontent among company fans.
And then I endured it, fell in love, and Apple to this day not only very successfully sells the 12-inch line of ultrabooks, but also equipped the USB Type-C MacBook Pro series, completely abandoning the classic USB 2.0 / 3.0, and indeed any additional ports.
Almost three years have passed since the MacBook was released, but users still have questions about the operation of the newfangled USB Type-C port. I am especially concerned about the selection of cables and accessories.
In this article we will deal with all the nuances of the new standard. I will try to present the material in such a way that after reading it there are no more questions, and everything becomes known about the USB Type-C ports in MacBook and MacBook Pro.
What is USB Type-C?
Despite the fact that engineers had already released three iterations of the USB standard, the main question remained open to them. It was necessary to provide normal food.
The pitiful current of 900 mA to feed the same laptop battery of 8-10 thousand mAh is clearly not enough. In addition, more power-demanding accessories began to appear on the market, and the tendency of manufacturers to make devices thinner and more compact forced them to abandon ports such as HDMI, Thunderbolt, classic USB, Ethernet.
Instead of 8-pin USB 3.0, 24-pin USB 3.1 Type C appears. Why are there so many? Judge for yourself:
The new USB Type-C specification opened up a number of new possibilities for users at once.
Firstly, USB Type-C has a new USB PD standard, according to which this port and the corresponding cables must be capable of transmitting current and power up to 100 W in both directions.
Secondly, the impressive data transfer rates. Thunderbolt 3 Alternate Mode can transfer data at speeds up to 40Gbps. Of course, with certain “if”, but more on that below.
Thirdly, it can transmit video with a resolution up to 5K. The speed here with a margin and the need for HDMI SIMply disappears.
Finally, USB Type-C is convenient in that “no matter how you plug it in,” it will work. It is bilateral. A logical continuation of the Lightning cable, but now not only for Apple devices.
And what then is installed in MacBook and MacBook Pro?
Before we figure out the choice of cables and USB Type-C accessories, you need to figure out those USB Type-C ports that are installed in MacBooks.
Alas, USB Promoter Group chopped a lot of firewood with the USB 3.1 specification, spawning several generations of ports and finally confusing users.
Unraveling this Gordian knot.
So, here are all generations of MacBooks and the corresponding USB Type-C ports installed in them.
That is, you should immediately understand that if you have a 12-inch MacBook, you can forget about Thunderbolt 3 support, which means it is stupid to overpay for support of this specification when choosing a cable.
MacBook 12 ″ supports video transmission via HDMI, VGA and DisplayPort (with appropriate adapters), but it will not work with Thunderbolt devices.
MacBook Pro 2016 and newer are much more interesting. 13-inch MacBook Pro models up until the recent update only had two of the four ports (those on the left) with Thunderbolt 3 support.
As of 2018, all four ports on TouchBar models are fully full-speed capable. The 12-inch MacBook has everything unchanged.
Where USB-C came from and where the problem crept in
The USB standard itself appeared back in 1994. USB 1.0 was conceived as a universal port for connecting all kinds of equipment to a PC. It was actively used only in the 2000s.
USB 2.0. Then it was time for USB 2.0. USB 2.0 cables are strictly oriented and come in two types of connectors: USB Type-A and USB Type-B. With the growing popularity of mobile devices, two more types of connectors will later appear: USB Micro-B and USB Mini-B.
Data was transmitted over two cables, usually green and white, and black and red were responsible for power.
The maximum data transfer rate for USB 2.0 is 480 Mbps. The main drawback of the standard is too low currents (no more than 500 mA), which often caused problems when connecting external drives.
USB 3.0. Determined to eliminate the shortcomings of USB 2.0, engineers are developing a new standard. USB 3.0. Blue USB became significantly faster and was able to transfer data at speeds up to 5 Gbps.
Perhaps this was due to the appearance of four additional communication lines, and, as a result, the growth of the maximum current to 900 mA.
In the fall of 2013, the specifications for the updated USB 3.1 Type-C standard were approved. Since then, life has ceased to be the same.
Choosing the right cable for specific tasks
The choice of USB Type-C cable directly depends on the task you are pursuing. This specification is very extensive, and it has certain limitations.
For maximum data rate (5K and 4K 60Hz)
40 Gbps is the maximum capacity of USB Type-C gen 2 with Thunderbolt 3 support. But this is under ideal conditions.
To achieve this speed, the cable length should not exceed 18 inches or 45 centimeters. Otherwise, the speed drops sharply.
But even here everything is not so SIMple. Thunderbolt 3 cords fall into two categories: passive and active. And you should pay attention to this if speed is important to you.
The first, with a length of two meters, transmit data at half the speed, that is, at the level of 20 Gbit / s, or even less.
Link to such an active cable from the Choetech company here.
The active ones have a special transmitter that controls the transmission rate along the entire length of the cable. Such laces maintain speed.
And here is an example of a certified passive Plugable cable up to 2 meters long. The speed here is no more than 20 Gb / s, but the price is much more pleasant.
For connecting USB 2.0 / USB 3.0 devices
Perhaps the only case when there are no problems with adapters. The same standard USB Type-C. USB adapter for 1,490 rubles. capable of delivering up to 5 Gbps.
This is exactly what the USB Type-C port is designed for on the 12-inch MacBook family.
For video transmission like HDMI
You’ve decided to connect an external monitor or TV to your MacBook or MacBook Pro. We figure out what to use to transfer a video stream in conjunction with USB Type-C.
First and foremost, determine which input port your external monitor or TV is equipped with.
For HDMI. There is a universal option that will not only add a standard USB 2.0 / 3.0 port and HDMI to MacBooks, but also duplicate USB Type-C. Costs 5 490 rubles.
For VGA. A SIMilar, but more archaic solution for VGA for the same 5 490 rubles.
For Thunderbolt 3. There are already several Thunderbolt 3 display models on the market (12-inch MacBooks go by). 0.8 meters of such a cable will cost 3,190 rubles.
The same option can be used for charging (up to 100W). Having overpaid 2 thousand rubles and buying this cable instead of a USB Type-C charging cable, you will get a truly universal lanyard that supports data transfer at speeds up to 40 Gb / s.
Important. Don’t chase length. Thunderbolt 3 2m and 1/2m cables are two different things.
But, here it is worth making some clarity.
USB Type-C supports charging power up to 100W. The set with MacBooks comes with a corresponding charging cable with an embedded controller that limits the maximum charging power.
The 12-inch MacBook comes with a cable with a maximum charging power of 61W. MacBook Pro 13 and 15-inch 87W respectively.
And this means only one thing: if you connect a 61-watt cable to an 87-watt charger and try to charge a MacBook Pro 15 ”, say, 2018 release, then charging will take place at a power of 61 watts. That is, one and a half times slower.
This is true for other certified manufacturers of charging cables as well.
Is it possible to connect a MacBook to a charging with increased power? Can. Instead of the included 29W power supply, you can power it with a 15-inch 87W MacBook Pro charger. It’s okay, but there won’t be a miracle and your MacBook won’t charge faster.
And yes, it is not harmful. The MacBook will only take as much as it can. By the way, the story is the same with the iPad.
To finally solve the problems with charging and get a cable “for all occasions”, you can opt for the original 2-meter USB-C cable for 1,490 rubles.