Lightning connector – what does it mean for each of us? Apple's new Lightning interface

A new connector standard called Lightning (from English - lightning) appeared with the release of new devices Apple iPhone 5, iPod Touch 5G, iPod nano7G, iPad 4 and iPad mini. This cable came out of the bowels of the company Double Helix Cables and it has a built-in authentication chip. There are no specifications for this cable, and one can only guess about the principle of operation. It is known that from the 30-pin old Lightning connector it has dropped to 8, but some sources claim that it is 9, taking into account the metal base of the contacts. It is completely digital and the chip in the cable itself determines what is currently connected, be it a media dock, Charger or some other device. The connector has eight pins on each side and does not have a mechanical key, which means it can be inserted in any position and it is not impossible to break it by trying to forcefully insert it the wrong way. Apple called this advantage of the cable - reversibility.

To do this, it would seem that the problem can be solved simply: electrically connect the contacts on the two sides of the plug crosswise, but it’s not so simple. Experts, having “ringed” the connector, found out that the contacts on the upper and lower parts of the plug do not have paired contacts, which means the plug cannot be turned over without changing the connection diagram. This paradox can only be explained in one way: the interface dynamically assigns pins depending on the orientation in which the connector is closed. It becomes clear that this is not an ordinary “camouflaged USB”. It is the dynamic assignment of pins and cable communication with the device that gives us what Apple calls adaptive interface. In principle, once the gadget and the switching chip have agreed on the purpose of the contacts, anything can be transmitted over them. For now lightning cable uses USB 2.0, but in the future nothing will stop it from using USB 3.0, FireWire or even Thunderbolt, putting more complex logic in the cable.

The first fruits of adaptability may appear soon. Some sites have published information that adapters for Lightning to VGA and DisplayPort will be released in the coming months. VGA requires 15 pins, and DisplayPort requires 20, so at least for this reason, the cable must already have a transmitter for the corresponding interface.

Why did Apple need a new interface, while there is a publicly available USB. The Lightning and Micro USB 2.0 connectors are approximately the same in size, but Lightning looks stronger and more reliable. Often the MicroUSB socket is broken out due to the incorrect placement of the connector.

And one more important point. It is logical to assume that when connected to a simple charger, several Lightning contacts can be used for power at once, for example data contacts, which will potentially allow the use of more powerful blocks for fast battery charging, because The higher the charging current, the faster the process. For the USB 2.0 interface, the maximum current on one port is 500 mA, for USB 3.0 - 900 mA. And, for example, the proprietary charger of the third iPad has a power of 10 W, which already gives a theoretical current of 2 A at a standard USB voltage of 5 V, and a 12-watt “charger” is supplied with the fourth iPad. So USB 2.0 and USB 3.0 cannot provide the power current needed to quickly charge tablets with such a large battery. As for MicroUSB 3.0, it is “fast”, but bulky and a less reliable connector than MicroUSB2.0. Lightning is ready to provide support for USB 3.0 and any other data transfer interface as soon as the need arises.

Lightning also outperforms a number of solutions that provide video stream output using specialized HDMI and DisplayPort transmitters. Apple's approach allows you to relieve the gadget from transmitter chips by integrating them into cables. As a result, we again get saving board space and power consumption. As well as reducing the price of the device for those who do not need a video output. In addition, Lightning eliminates the additional headache of deciding which connector to output the video stream through. The Mini HDMI option not only diverges from the minimalist design of Apple gadgets, but also - again and again - requires additional space, despite the fact that it will be useful to an absolute minority.

This is actually a very smart and forward-thinking solution that may become a trend over time: decoupling the mechanical connector form factor and pin switching from the specific bus. Adaptive interfaces and smart cables are the best way to reduce component volume and power consumption of a mobile device, providing rich functionality and growth potential for years to come.

Apple has released a special adapter from the Lighting connector in the iPhone 5 to the usual micro-USB format. The fact is that last year the European Union passed a law according to which every phone must support this standard.

And also an adapter for your old 30-pin connector.

Apple decided to ditch the 9-year-old 30-pin connector in favor of a new, smaller alternative. Why such changes?

iPhone 5 offers many improvements over its predecessor, including a larger screen, faster performance, LTE support and an improved camera.

However, for those migrating from an older iPhone, there is one more change that may seem the most significant, at least when it comes to compatibility: a new connector. Apple decided to ditch the 9-year-old 30-pin connector in favor of a new, smaller alternative. Why such changes? And what do they mean for each of us and our current accessories? Let's take a closer look at the new connector, called Lightning.

30 contacts, 9 years

Apple's 30-pin connector has been a staple of iPods, iPhones, and iPads since the introduction of the third generation of iPods back in 2003. While most media players offer a simple USB connection to transfer data and charge the device, Apple's single port covers many more functions - charging, audio output, playback control and fast data syncing are among the first to appear.

Over the years, the 30-pin port has gained some new features (HD video output, photo import, USB input) while dropping others (like FireWire charging and data transfer), but it has continued to serve us well. , and Apple: along with the universal dock design, the 30-pin port gave us hope - by purchasing an accessory with a dock connector (be it speakers or car chargers), we could be sure that the product would work with any i-device .

True, it was not without its flaws. Firstly, the connector was somewhat fragile, and as a result, your accessory or, even worse, your iPhone or iPod could fail. The connector's thin profile and single-sided design made the connector more difficult to use than, say, a standard USB port—depending on the device and accessories, aligning the connector and port could be quite a challenge. Finally, the 30-pin connector took up too much space, especially as Apple's phones, tablets, and media players continued to trend smaller.

First Thunderbolt, then Lightning

Once upon a time in Apple history the day came when the company introduced the iPhone 5 and new iPods to the public. It also became rotatable for the connector - new models have a new connector called Lightning.

The new connector uses an 8-signal design that works in both orientations, meaning there is no longer any reason to worry about making the connection correctly. According to Apple, the Lightning connector is not only easier to use, but also more durable than its predecessor. Moreover, the company is positioning the new connector as completely digital.

Of course, another big advantage of the new connector is its size. It's 80% smaller than a 30-pin connector, meaning it requires less space on your device, not to mention reducing the amount of internal circuitry required to support the connector's functionality. The new smaller connector is one of the reasons why the new iPhone is 20% thinner than the iPhone 4S (the other reason is that the iPhone's screen sensors are now integrated into the display, which is why the display itself is thinner).

Adapt or buy?

Easier to use, stronger, smaller - really like it? And it would seem that everything is fine, but the Lightning connector ends all hopes of compatibility of new Apple devices with millions of accessories with a 30-pin connector. New iPhones and iPods are equipped with a USB-Lightning cable, but not an adapter for using new devices with old accessories.

If you have already invested a lot of money in purchasing accessories, you will agree, but you are unlikely to want to change anything. This is where the Lightning to 30-pin adapter comes to the rescue for $29 or $39 (20 cm cable), each of which allows you to connect accessories with a 30-pin connector to the new iPhone or iPod model.

The adapters support analog and USB audio, and also allow data synchronization and charging. However, according to Apple, the adapters do not support video output. Moreover, some 30-pin accessories are not supported.

One way or another, but even with the addition of an adapter, the appearance new technology means nothing more than the obsolescence of some accessories.

In general, the variety of manufacturers (Digitus, Just Mobile, JVC, Belkin...) that can offer alternative adapters for iPhone 5 may well satisfy consumer demand. And it is likely that they will go on sale in the near future.

More wireless, but still wired

What's perhaps most exciting about the move to the new Lightning connector is that it increasingly reflects the way we use iPhones and iPods. Many things that we previously did using wires can now be done using wireless technology. Bluetooth for speakers and headphones; Wi-Fi for audio and synchronization; iCloud for wireless content downloading and backup. In other words, Apple believes that we no longer need physical connections.

However, the latter remain necessary, for example for charging, faster sync and better sound quality (don't be fooled, "wireless" charging also needs a cable and a physical connection). Until wireless charging, like the one found in the new Lumia 920, becomes ubiquitous and can be built into the iPhone without making it thicker, we're stuck in a world of cables. According to Apple, the new connector promises to serve its users for many more years.

And once again, finally, we remind our readers that, unfortunately, there are still no official deliveries of iPhones in Ukraine. Perhaps they will appear with us after the advent of 3G and 4G. But this is just our guess.

Which are openly called competitors of the iPhone 8 and the device manufacturer, Google, began selling an adapter from USB Type-C to 3.5 mm, since the new products lack the usual audio jack. Now this is a common practice, but the search giant asked for as much as 20 dollars for its adapter.

Almost 50,000 rubles will have to be paid for a set of 18 adapters for Apple devices presented in the assortment of the Russian online store, the site calculated. When making calculations, only the retail price of branded accessories produced by Apple itself and available for purchase at the moment was taken into account.

After working in the consumer electronics industry for a long time, Apple was able to identify another source of user irritation. Connecting charging cables in the dark is not an easy process, especially if the mobile device is completely discharged and its screen is not capable of functioning as a flashlight. It looks like they have decided to put an end to this problem once and for all.

I wish the new iPhones had already come out. It will be possible to stop guessing what they will look like and what Apple will or will not equip its devices with. There are a lot of rumors going around. They talked about the transition to the USB Type-C connector, and about the disappearance of the , which the company gives customers bundled with the iPhone 7 and . Analysts from Barclays believe that in this regard everything will remain the same.

Many people, as a rule, want to order goods from the USA, rather than overpay their crazy markups to local stores. However, sometimes it turns out that delivery from another country is too expensive, and it turns out that buying a particular product in Russia is cheaper than ordering it elsewhere. But this rule does not always work, and if the package is even lighter than a kilogram (for example, an iPhone or), its delivery will cost very little.

Not long ago the Wall Street Journal published. According to them, the new iPhone, which will be presented by the company this year, will surprise us with the appearance of a USB-C connector, which will replace the Lightning connector. It's hard to believe, but one cannot ignore the credibility of the Wall Street Journal and their sources. However, there were those who were ready to doubt all this.

Yesterday, many analysts, citing their own sources, began to claim that Apple will abandon Lightning in the new iPhone. The news immediately caused a wide resonance, since accessories with Lightning had just begun to appear on the market, and new ones were no exception. There is probably a plan for this as well.

We know a lot about Apple's future smartphone, but we haven't heard anything like this yet. The authoritative publication Wall Street Journal believes that a USB-C connector will appear instead of the Lightning connector. It's extremely hard to believe, but the Wall Street Journal rarely writes about anything they're not sure about. USB-C is actively used by Apple in the MacBook, but has not previously appeared in the company's portable devices.

One of the most discussed questions about the new iPhone now is how the smartphone will be charged. And we are not talking about (we seem to have already come to terms with this), but about the type of connector that will be responsible for this functionality. Yes, we are talking about -C now.

I don't think you should talk about the company's strange attitude towards connectors. On the one hand, Apple loves USB Type-C connectors, and the company has put a lot of effort into improving this standard. On the other hand, the company uses its own Lightning connector in its portable devices. One can only guess why Apple came to a single standard, but it is worth noting that the company's decisions are difficult.

The official Apple technical support website has been updated with a warning about the dangers of using counterfeit components and accessories. According to company representatives, more than 90% of retail products marked “Made for iPhone” are produced using artisanal methods and are unsafe for both the connected device and its owner. Be vigilant, they call us in.

Apple has never been shy about introducing proprietary standards for anything - both in “software” and “hardware”. Are conventional solutions not suitable? OK, let's come up with our own. This has always been most clearly manifested in the choice of interface for connecting the computer with peripheral devices.

Some interfaces generated by Apple never left the cozy “Apple” ecosystem and died there, eventually succumbing to open standards. For example, one day there was a need to pass a video signal, power supply and USB bus to the monitor via one cable, and the ADC (Apple Display Connector) standard was born, combining all of the above. But over time, it still had to be replaced by DVI. In other cases, Apple teamed up with third-party manufacturers and in every possible way promoted the new standard to the masses. A long-standing example of such expansion in the hardware sector is the FireWire bus. Fire Wire, being a more technologically sophisticated and faster interface compared to USB, has not kept up with the latter in distribution (due to the high cost of components), but has found both its user and a specific market niche.

A more recent one is the Mini DisplayPort connector created by Apple (although Apple is not the author of the interface as such), which has already been picked up by manufacturers of laptops and video cards. Then Mini-DP was additionally used for the Thunderbolt bus from Intel, in the development of which Apple was directly involved. Its charm became clear as soon as the developers decided on the positioning and the masses stopped contrasting Thunderbolt with USB 3.0. There were so many exotic solutions for connecting high-grade peripherals to a PC, and Intel, together with Apple, took it and made a single convenient standard.

For Apple haters, all this looks like some kind of whim, a desire to isolate itself from competitors and simply be different from others at any cost. And arrogant people who imagine who knows what about themselves, as we know from school, are strongly disliked. The public is especially irritated by Apple's stubborn reluctance to join the common interface for synchronizing and charging mobile gadgets, USB. While all smartphones and even some dumb phones adopted the Micro USB standard, Apple to the last held on to its 30-pin connector, which debuted back in 2003 with the third generation of iPod, and now looks like a complete, monstrously awkward anachronism . The fifth iPhone retired the 30-pin connector, but, contrary to expectations, it was replaced not by the generally accepted Micro USB, but by another proprietary standard - Lightning. Naturally, it began to pour out from all sides: “And again Apple did everything differently from people!” Even worse, the Lightning cable is said to have sinister authentication chips built into it so that Apple can allegedly charge “those stupid fanboys” $19 for branded accessories and extract licensing money from peripheral manufacturers. Well, how can you not be indignant?

Long-time users of i-devices are also indignant, having collected a collection of i-peripherals: all kinds of cables, docking stations, speaker systems and sometimes much more exotic equipment with a 30-pin connector. Even Russian officials, who this summer posted an auction for a Toyota Land Cruiser 200 in luxury trim on the government procurement website, terms of reference They specifically indicated “USB/AUX connector (with the ability to connect an iPod).” True, the auction was canceled before Apple changed the interface. You know who to thank for this even without us.

Seriously, at first glance it’s really not clear why Apple needed a new proprietary interface, while there is a publicly available USB. Lightning specifications have not yet been published, and one can only guess how it works, how it differs from USB, and whether it differs in anything other than the connector. But something has already become known. It seems that Lightning is a complex and interesting contraption, the purpose of which is not limited to giving Apple the opportunity to profit from trading licenses. Let's try to bring together fragments of information on this topic found on the Internet into a single picture.

⇡ Digital, adaptive, durable, reversible

Apple doesn't talk much about how Lightning works, limiting itself to pointing out the main advantages of the interface: it is completely digital, adaptive, durable and reversible.

Strength is the easiest point that doesn’t require much explanation. Even simply reducing the number of pins from 30 to 8 increases the strength of both the male and female connectors. In addition, the connector design has become simpler, the connection is tighter, and the plug does not dangle back and forth, as was the case with the 30-pin connector.

The Lightning connector in the iPhone 5 is firmly fixed to the case (photo iFixIt)

The Lightning connector is approximately the same size as Micro USB 2.0, but again has a simpler design. The Micro USB 3.0 connector is already twice the size, and the need for backward compatibility with 2.0 cables has made it even more complex and therefore less reliable. In addition, in the iPhone 5, the Lightning socket is not soldered to the motherboard, but is screwed directly to the metal case. Most manufacturers of smartphones with Micro USB do not do this and solder the connector onto the board. For the careful user, all this is not relevant, but it must be admitted that the Lightning connector is much better prepared for less careful treatment compared to both the 30-pin connector and Micro USB.

Lightning and Micro USB connectors are approximately the same size, but Lightning looks stronger (photo by The Gadgeteer)

The reversibility of the interface is partly related to the theme of durability. In practice, this term means that the plug can be inserted in any orientation. There is no mechanical key in the connector, which means it cannot be broken by trying to forcefully insert it the wrong way. But the most interesting thing about Lightning begins with reversibility. It would seem that the problem can be solved simply: electrically connect the contacts on the two sides of the plug crosswise, but...

A specialist from Double Helix Cables (actually, a cable manufacturer) rang the Lightning connector and sketched out a diagram that had already been republished several times by hand. What interests us is drawn in the lower left corner of the piece of paper. The pins on the top and bottom of the plug are numbered 1 through 8. Pins 1 and 5 on the top are actually connected diagonally to the bottom pins 8 and 4 respectively. From the same note it is known that the V- (“minus” power supply) of the USB bus is connected to pin 1/8. It is also connected to the metal shell of the plug. But the rest of the upper contacts do not have a pair on the lower part, so that the plug can be turned over without changing the connection diagram. This paradox can only be explained in one way: the interface dynamically assigns pins depending on the orientation in which the connector is closed.

Lightning plug contact diagram (photo by Appleinsider)

By the way, note that the diagram does not indicate the pin corresponding to V+ in the USB bus. It is not clear how the author of the note called the Lightning cable. It is most likely that he was not connected to the phone. In this case, the absence of V+ is explained by the following hypothesis: the assignment of contacts occurs inside the cable and, while the phone is not connected, the cable simply does not turn on the power. This is the main function of the mysterious “authentication” chip.

The chip itself in the Lightning plug was indeed discovered and studied in detail by Chipworks, a reverse engineering laboratory. Several microcircuits are soldered onto the miniature board, but only a chip labeled BQ2025, apparently manufactured by Texas Instruments, contains more or less complex logic. There is no information about it on the TI website, but from the pictures of the crystal it was possible to find out that the chip is compatible with TI’s proprietary SDQ interface. In turn, SDQ support means the presence of a CRC generator. Chipworks themselves conclude that CRC in Lightning is precisely used for device authentication. But in principle, any serial interface cannot do without a CRC to control the integrity of packets, so we can say that opening the cable did not allow us to refute the authentication hypothesis, but it has not yet received convincing confirmation. By the way, SDQ uses only one core for the signal. Perhaps this is the “non-transitioning” pin 5 in the Lightning connector, through which the chip tells the iPhone what exactly it was just connected to. A blog on Asia.CNET says that the phone turns on when it detects a Lightning cable, even if the other end is not connected to USB. This fits with the hypothesis that the device somehow interacts with the chip inside.

Mysterious chip in the Lightning plug (photo by Chipworks)

It's the dynamic pin assignment and cable-to-device communication that gives us what Apple calls an adaptive interface. In principle, once the gadget and the switching chip have agreed on the purpose of the contacts, anything can be transmitted over them. The existing Lightning to USB 2.0 cable simply passes USB signal lines to the device. This cannot be done with USB 3.0, since it uses nine pins, while the Lightning connector already has only eight, of which at least one is used for communication with the chip. But this does not mean at all that the Lightning concept is exhaustively described by the words “tricky USB 2.0, (possibly) with authentication.” Nothing prevents in the future from embedding more complex logic into the cables, for example, a USB 3.0 host controller or another interface that will connect to the gadget’s SoC via some internal serial bus. It is clear that such a cable will cost even more, but in doing so, Apple has ensured longevity for the interface. The good old 30-pin connector lasted nine years due to the fact that everything was initially integrated into it, including simultaneous support for USB and FireWire, and even analog outputs. Lightning, thanks to its adaptability, can live no less.

The first fruits of adaptability may appear soon. The website has published information that adapters for Lightning to VGA and DisplayPort will be released in the coming months. VGA requires 15 pins, and DisplayPort requires 20, so at least for this reason, the cable must already have a transmitter for the corresponding interface.

And one more important point. It is logical to assume that when connected to a simple charger, several Lightning contacts can be used for power at once, which will potentially allow the use of more powerful units to quickly charge the battery, because the higher the charging current, the faster the process. For the USB 2.0 interface, the maximum current on one port is 500 mA, for USB 3.0 - 900 mA. And, for example, the proprietary charger of the third iPad has a power of 10 W, which already gives a theoretical current of 2 A at a standard USB voltage of 5 V, and a 12-watt “power supply” is supplied with the fourth iPad. Note that the USB Battery Charging 1.2 Compliance document is currently in development, which allows the use of dedicated USB ports for charging with a maximum current of up to 5 A due to the D+ and D- pins, which are usually used for data transfer. But this is in development, and for now all “high-precision” USB implementations are made by manufacturers as a private initiative.

⇡ Where is my $1 cable?

According to rumors, Apple has changed the terms of the MFi program, which regulates relations with manufacturers of accessories for i-devices. Now peripherals will be produced only in those factories that Apple approves. They also say that Apple will control the supply of Lightning connectors to ensure that they are used only in devices that meet certain criteria. Anandtech found out that the connectors will be supplied in four versions: USB Host, USB Device, charging only, and also a connector for serial connection (apparently, this refers to the iPod Acessory Protocol). Each option comes in a physical version for the cable and for the docking station.

Meanwhile, companies not allowed to the feeding trough will still fight for their bread. A certain Chinese company iPhone5Mod announced that it was able to create a connection to the iPhone 5 using a “hacked” chip, although the prototype in the video, the manufacturer admitted, works with the original chip received from an Apple supplier.

Thus, the only way that accessory manufacturers will be able to reduce their cost is to use third-party switching chips (if they actually exist and will actually cost less). Therefore, you can forget about non-original cables for $1. This is the price of progress.

I feel, I feel a wave of popular indignation rising. To justify Apple, it can be said that immediate profit is not the only, and perhaps not the main, motive for its strict licensing policy. It’s just that Apple probably wants to eliminate cases where an unlicensed miracle device mixes up the contacts in the connector and shorts something out. And in general, there will be less junk with an iPhone dock on the market.

⇡ Alternative solutions

Now let's summarize and see which of the functions that Lightning has could be implemented and which could not be implemented if Apple had not “invented” and chosen Micro USB.

Firstly, nutrition. It is unlikely that the presence of a Lightning connector and a 12-watt power supply on the fourth iPad is a coincidence. Both USB 2.0 and 3.0 in their current implementation cannot provide the power current required to quickly charge tablets with such a large battery.

But let's say that this may not be so important, and until the final version of USB Battery Charging 1.2 Compliance has been adopted, you can tolerate slow charging. Let's say it would be more important to implement compatibility with USB 3.0, and mobile devices already need a high-speed interface for synchronizing with a PC. Alas, such a solution would entail the need to use a larger connector, and also to either find space on the board for a separate host controller chip, or integrate it into the SoC, where it would still take up some area in addition to the USB 2.0 logic and increase total energy consumption. In addition, there is a suspicion that the Apple A6 SoC will still not support USB 3.0 with such performance that there is any point in dealing with these difficulties at all. The issue of SoC power is especially relevant in the context of video output using USB Video Device Class (in theory, the bandwidth of USB 3.0 allows you to broadcast a video stream in 1080p resolution with a frame rate of 120 FPS). Lightning is ready to provide support for USB 3.0 and any other data transfer interface as soon as the need arises, and the corresponding computing capabilities.

Lightning also outperforms a number of solutions that provide video stream output using specialized HDMI and DisplayPort transmitters. Apple's approach allows you to relieve the gadget from transmitter chips by integrating them into cables. As a result, we again achieve savings in board space and power consumption. As well as reducing the price of the device for those who do not need a video output. In addition, Lightning eliminates the additional headache of deciding which connector to output the video stream through. The Mini HDMI option not only diverges from the minimalist design of Apple gadgets, but also - again and again - requires additional space, despite the fact that it will be useful to an absolute minority.

MyDP implementation from Analogix Semiconductor (brockerhoff.net diagram)

A more elegant option is the currently in development MyDP standard, which reduces the number of DisplayPort lanes from 20 to 5, allowing the signal to be transmitted through a standard Micro USB 2.0 connector. But this is again a separate transmitter chip plus a circuit that switches the port operating mode between USB and video output. A close replacement for Lightning in terms of video output could only be the MHL (Mobile High-Definition Link) architecture, which is built on the same principle: data is transmitted via a USB connector using a special protocol, and in the cable it is recoded to HDMI using (dammit! ) a separate chip, which also costs money. And to switch the port operating modes, a separate circuit is again needed. An alternative is to make another custom connector.

⇡ Conclusion

Here's what we can say about the Lightning interface now. Some of what is written here are solid facts, some are just assumptions. And yet, there is already enough information so that the choice in favor of another proprietary interface does not seem like a pure attempt to take money from workers. This is actually a very smart and forward-thinking solution that may become a trend over time: decoupling the mechanical connector form factor and pin switching from the specific bus. Adaptive interfaces and smart cables are the best way to reduce component volume and power consumption of a mobile device, providing rich functionality and growth potential for years to come.