Connector usb c: What Is USB-C? An Explainer

What Is USB-C? An Explainer

Landing on a single standard to rule them all is an elusive aim in the realm of personal technology. At best, you end up in a format war, and one faction emerges victorious for a few years until an entirely new technology takes it out. VHS ate Betamax, then was ousted by DVD, which faded in the face of Blu-ray (a standard that itself knocked off its chief rival, HD DVD), now facing its own mortality at the hands of online streaming services.

But USB-C is different—and perhaps it’s even as truly universal as its acronym (Universal Serial Bus) suggests. USB-C ports are now found on all manner of devices, from simple external hard drives to high-end laptops and the latest smartphones. While every USB-C port looks the same, not every one offers the same capabilities. USB-C may now be ubiquitous, but it doesn’t serve the same functions everywhere. Not by a long shot.

Here’s a guide to everything USB-C can do, and which of its features you should look for when buying your next USB-C device.

Explained: What Is USB-C?

What Is USB-C?

USB-C is an industry-standard connector for transmitting both data and power on a single cable. The USB-C connector was developed by the USB Implementers Forum (USB-IF)(Opens in a new window), the group of companies that has developed, certified, and shepherded the USB standard over the years. The USB-IF counts more than 700 companies in its membership, among them Apple, Dell, HP, Intel, Microsoft, and Samsung.

This broad acceptance by the big dogs is important, because it’s part of why USB-C has been so readily accepted by PC manufacturers. Contrast this with the earlier Apple-promoted (and developed) Lightning and MagSafe connectors, which had limited acceptance beyond Apple products and became obsolete, thanks in no small part to USB-C.

USB-C is so broadly accepted that the European Union, hoping to simplify digital life, will require devices to use it for battery charging starting in 2024. That means future iPhones will have USB-C ports instead of Lightning connectors.

Is USB-C the Same as Micro USB or USB 3.0?

The USB-C connector looks similar to a micro USB or rectangular USB 3.0 connectors at first glance, though it’s more oval in shape and slightly thicker to accommodate its best feature: flippability.

(Credit: Zlata Ivleva)

Like Lightning and MagSafe, the USB-C connector has no up or down orientation. Line up the connector properly, and you never have to flip it over to plug it in; the “right way” is always up. The standard cables also have the same connector on both ends, so you don’t have to figure out which end goes where. That has not been the case with all the USB cables we’ve been using for the past 20 years. Most of the time, you have different connectors at each end.

USB-C and USB 3.2: The Numbers Beneath the Port

Where USB-C gets tricky is in the numbers that get attached to the ports. The most common speed that USB-C connectors are rated for is 10Gbps. (That 10Gbps is theoretically twice as fast as original USB 3. 0.) USB-C ports that support this peak speed are called “USB 3.2 Gen 1×2.”

The minor wrinkle is that USB ports with 10Gbps speeds can also exist in the original, larger shape (the USB Type-A rectangles we all know), and are dubbed “USB 3.2 Gen 2×1.” With the exception of some desktops, though, it’s more common to see 10Gbps-speed USB ports with USB-C physical connectors. Note: Some older USB-C ports support just 5Gbps maximum speeds, so it’s important to look for a “USB 3.2 Gen 1×2” or “10Gbps” designation to verify that a given USB-C port supports 10Gbps transfers. That said, all of these ports are backward-compatible, just at the speed of the slowest element.

Confused yet? Further complicating matters: The number scheme around USB 3 has been in flux, which has made references to these ports something of a swamp. Until recently, many USB-C ports carried the USB 3.1 label (“USB 3.2” was not yet a thing) in Gen 1 and Gen 2 flavors, and some spec sheets continue to reference the older name, along with SuperSpeed branding. In a confusing twist, the USB-IF decided to eliminate the use of “USB 3.1” in favor of these various flavors of USB 3.2, as outlined below in this handy decoder chart…

The USB 3.2, USB 3.1, and SuperSpeed designations you see above on each line are equivalent, just differing in name. If you see a USB 3.1 label, it’s best to inquire about the maximum transfer speeds of the port directly with the device manufacturer or reseller.

As you can see above, some USB-C ports use the USB 3.2 Gen 2×2 specification, with maximum speeds of 20Gbps. The USB-IF decided on “2×2” because this standard doubles the data lanes within a USB-C cable to achieve the 20Gbps transfer speed. These ports have not been widely available. They will likely go by the wayside in favor of another emerging flavor of USB-C ports, supporting USB4, which the USB-IF has announced will eventually support data speeds up to 120Gbps.

To reduce confusion, the USB-IF also intends to do away with numbered USB versions in the future, instead encouraging device makers to refer to a port’s top speed, as in “USB 20Gbps. “

Can You Go From USB-C to DisplayPort?

You might think of your old USB Type-A port simply as a data port for connecting drives or peripherals like mice. But USB-C, depending on the specific port’s implementation, can do much more. One of USB-C’s most useful skills, when designed thus, is delivering enough power to charge the host device, such as a laptop or a smartphone. In fact, many lightweight laptops that have USB-C ports use them in place of a traditional barrel-style connector as the only option for attaching an AC adapter.

USB-C’s support for sending simultaneous video signals and power means that you might be able to connect to and power a native DisplayPort, MHL, or HDMI device, or connect to almost anything else, assuming you have the proper adapter and cables. (See below for more on adapters.) The USB-C spec even factors in audio transmissions over the interface, but so far it has not replaced the 3.5mm headphone jack on computers to the same degree as it has on phones and tablets.

Make sure to check the specs on any PC you’re thinking of buying, because not all USB-C ports are alike. So far, every one we’ve seen supports both data transfers and connected-device power delivery over USB-C (though not necessarily charging of the host device). But while the USB-C standard supports connecting DisplayPort and/or HDMI displays with an adapter (via the DisplayPort-over-USB protocol), not every PC maker has connected the ports to every system’s graphics hardware. Some USB-C ports on a system may support video-out connectivity, while others may not; or none may. And some devices add extra layers of security or other requirements to connect USB-C peripherals, including Macs, which requires user approval before the accessory can communicate starting with macOS 13 Ventura. Looking at the details is important.

Is Thunderbolt the Same as USB-C?

Perhaps the most useful protocol that a USB-C port can support is Thunderbolt, currently in its fourth generation. Thunderbolt 4 adds support for up to 40Gbps of throughput, alongside reduced power consumption and the ability to move as much as 100 watts of power over the interface.

A USB-C port with support for Thunderbolt means that a single cable is all you need to push power and transfer a large amount of information (up to and including video data for two 60Hz 4K displays) to and from even a complex device like a computer, something many laptop manufacturers have been quick to take advantage of. Some models of Apple’s MacBook Pro boast four Thunderbolt connectors, which is as many as we’ve seen to date, and it gives you more expansion potential than you ever had with earlier versions of USB.

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Thunderbolt vs. USB-C: What’s the Difference?

(Credit: Zlata Ivleva)

Now, like with DisplayPort over USB-C, not every USB-C port you see necessarily has Thunderbolt support. Check a device’s spec sheet or documentation for the Thunderbolt details to be sure. Some devices may have more than one USB-C port, with only some supporting a Thunderbolt spec.

Thunderbolt 4 doesn’t offer any major improvements over Thunderbolt 3 for most users, and the two protocols appear similar at first blush. Both use the USB-C physical connector and offer a maximum throughput of 40Gbps, so speed’s not the issue here. And both offer at least 15 watts and up to 100 watts of charging power.

The way in which Thunderbolt 4 evolves Thunderbolt is by doubling the minimum video and data requirements of Thunderbolt 3. Thunderbolt 4 supports sending a video signal to two 4K displays, or to one 8K display, while Thunderbolt 3 is required to support only a single 4K display. Also, while Thunderbolt 3 systems have to support only a 16Gbps data rate via PCI Express, Thunderbolt 4 will double that requirement to 32Gbps. This may benefit users who regularly transfer gigantic video or data files from storage drives to their PC for editing.

Adapters, Cables and USB-C Hubs

USB-C is electrically compatible with older USB 3.0 ports. But because of the shape of the newer port, adapters or cables with appropriate plugs are indeed required if you want to connect anything that doesn’t have the USB-C oval shape.

Sometimes a new laptop will come with these; in other cases, you may have to purchase them separately. Apple, for instance, sells a variety of USB cables and adapters for connecting USB-C to other technologies such as Lightning or Ethernet. You can also find a variety of these for PCs if you browse online retailers. Some even support older or more esoteric protocols, to ensure a device you have from years ago will work on today’s hardware. It’s easy to find USB-C-to-DVI adapters, for example, but we’ve also come across some that split to two RS-232 serial connections.

(Credit: Satechi)

The good news, though, is that if you invest in a couple of normal USB-C cables, they will work with anything and everything that supports USB-C, regardless of generation. Note, however, that that does not extend to Thunderbolt. Though Thunderbolt 3 and 4 use a USB-C physical connector, you’ll need an appropriate Thunderbolt-specific cable to guarantee compatibility and full speed. This cable will have a USB-C connector at both ends but with a lightning symbol on each. It’ll also be significantly pricier than a standard USB-C. Again, see our Thunderbolt 4 primer for more on the cable issues.

The Best USB and USB-C Hubs

Plus, newer docks for PCs and docks for Macs have now widely integrated USB-C. Having only one USB-C port is not a problem: You can find USB-C docking solutions available, both from PC manufacturers like Dell and HP, and from third-party accessory makers like Belkin and OWC. These docks can recharge your laptop, give you access to extra ports (including Ethernet, HDMI, USB 3.0, and VGA), and add support for multiple monitors.

Do You Need USB-C?

The presence (or absence) of a USB-C port is increasingly becoming a consideration when buying a PC. If you buy an ultrathin laptop, it will almost certainly have at least one USB-C port, which will catapult you into the ecosystem automatically. If you’re more of a lover of desktops, you’re certain to find the ports there, too, with at least one on the motherboard-side I/O panel and likely more on high-end and gaming desktops. Some desktops and aftermarket PC cases are putting one on the front panel, too. (Desktop DIY types should know, though, that a USB-C port on a PC case’s front or top will require a specific USB-C header connector at the motherboard end, and only late-model motherboards will have these.)

Even if you don’t need USB-C now, you will before long. We’re only scratching the surface of what USB-C can do, but one thing is certain: The next generation of cross-platform connectors is quickly replacing the old guard just as the original USB standard replaced Apple Desktop Bus (ADB), FireWire, parallel, PS/2, SCSI, and serial ports on Macs and PCs. USB-C truly is one port to rule them all.

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USB Type C | CUI Devices

USB Type C Receptacles and Plugs

CUI Devices’ USB Type C connectors conform to the USB 2.0, USB 3.2 Gen 2 (previously USB 3.1 Gen 2), USB 3.2 Gen 2×2 (previously USB 3.2), or USB4 40 Gbps standards. Supporting data transfer speeds up to 40 Gbps and power delivery up to 240 W at 48 V, these USB Type C connectors offer 3 A or 5 A current ratings for faster power charging and high durability up to 10,000 mating cycles. Available in vertical and horizontal orientations with mid mount SMT, cable mount, and SMT mounting styles, the UJ receptacle connector series and UP plug connector series feature a reversible connector interface for simple and reliable mating. These USB Type C features combine to provide designers with a compact, versatile solution for a variety of I/O applications in consumer and portable electronic devices. CUI Devices also offers a range of 60 W or 100 W power-only USB Type C receptacles where the data transfer pins have been removed, providing a cost-effective solution for designs where charging or power is the sole function.

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Up to USB4 standard or power-only

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All You Need to Know About USB Connectors and Standards

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An Introduction to Power-Only USB Type C Connectors

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Guide to usb connectors and usb cables

USB (English Universal Serial Bus – “universal serial bus”) – was developed in 1990 in order to simplify the connection of peripheral devices to a computer. It has become popular due to its compatibility with many platforms and operating systems, as well as its low cost and ease of use. Most modern computers have multiple USB ports, as do most home and office equipment, including printers, cameras, modems, and portable storage devices.

The USB standards are developed and maintained by the USB Implementation Forum (USB-IF), an industry organization. In its original specification, USB only categorized into two connector types: A and B. Changes in specifications and manufacturer requirements have expanded the range of connectors used for USB devices, but most USB products still use the A and B connector interfaces.

Select the USB connector you would like to learn more about:

USB type A

USB type B

USB type C

Micro USB A

Micro USB B

USB Mini-b (5-pin)

USB Mini-b (4-pin)

USB 3.0 A Type

USB 3.0 B Type

USB 3.0 Micro B

More Connectors:

Micro USB AB

USB Mini-b (Fuji)

USB type A

Found on computer host controllers and hubs, the Type A connector is a flat, rectangular interface. This interface holds the connection in place with friction, making it very easy for users to connect and disconnect. Instead of round pins, the connector uses flat pins that withstand constant connection and disconnection very well. The Type A connector provides a downstream connection that is intended for use exclusively on host controllers and hubs. It is not designed to transfer information from the device to the computer. This is critical because the host controller or hub is designed to provide 5V DC on one of the USB pins. A-A cables are sometimes used to connect USB devices with a Type A jack to a computer or other USB device, or to transfer data between two computers.

Note. Typically, an A-A cable is not used to connect two computers, or to connect a USB hub between two computers. This can cause irreparable damage to your computer and even cause a fire. Before using an A-A data cable, consult the manufacturer.

Female:

USB type B

The Type B connector is for use with USB peripherals. The Type B interface has a square shape with slightly beveled corners. Like the Type A connector, it uses the friction of the connector body to secure it. Receptacle B is an upstream connector that is used for peripherals only. For this reason, most USB devices require an A-B cable.

Female:

USB type C

The USB-C or USB type C connector is the latest USB connector on the market. The USB-C connector is reversible/symmetrical and can be connected to any USB-C device. The USB-C cable can carry USB 3.1, USB 3.0, USB 2.0, and USB 1.1 signals. USB-C is usually paired with USB-A, USB-B, USB Micro-B, and other USB connectors while supporting previous versions of the USB specification. USB-C can be adapted to work with each of these legacy connectors. When connecting two USB 3.1 devices, the USB-C cable will support data transfer rates twice the speed of existing USB technology (up to 10 Gbps), improved power output up to 20 volts, 5 amps and 100 watts for power and charging, as well as a built-in support for DisplayPort video and 4-channel audio (speaker and microphone).

Micro-USB B

This USB-IF recognized connector can also be found on newer mobile devices such as mobile phones, GPS devices, PDAs and digital cameras. Micro-USB B is a physically smaller connector than USB Mini-b, while still supporting 480 Mbps high data transfer rates and On-The-Go functionality. The connector can be easily identified by its black receptacle and compact 5-pin design.

USB Mini-b (5-pin)

One of the disadvantages of connector B is its size – almost half an inch on each side. Because of this, interface B has become unsuitable for many compact personal electronic devices such as PDAs, digital cameras, and mobile phones. As a result, many device manufacturers began miniaturizing USB connectors, starting with Mini-b. This 5-pin Mini-b is the most popular type of Mini-b connector and the only one recognized by USB-IF. By default, the Mini-b cable is assumed to have 5 pins. This connector is quite small, about 2/3 the width of connector A. It is also intended for use in the newer USB On-The-Go standard, which allows peripherals to communicate in the presence of a host controller.

USB Mini-b (4-pin)

Instead of the usual 5-pin Mini-b, this unofficial connector is used in many digital cameras, especially some Kodak® models. It resembles the shape of a standard Type B connector with chamfered corners, but is much smaller.

USB 3.0 0 type A

This Type A connector, known as “SuperSpeed”, is commonly found on host controllers in computers and hubs and is a flat, rectangular interface. This interface holds the connection in place with friction, making it very easy for users to connect and disconnect. Instead of round pins, the connector uses flat pins that withstand constant connection and disconnection very well. Connector A provides a downstream connection that is intended for use exclusively on host controllers and hubs. This connector is similar in size and shape to the Type A connector used in USB 2.0 and USB 1.1 devices. However, USB 3.0 Type A has additional pins that USB 2.0 and USB 1.1 Type A do not. The USB 3.0 connector is designed for USB SuperSpeed devices, however it will transfer data from slower connectors and is backwards compatible with USB 2.0 ports. USB 3.0 A connectors can be distinguished from previous versions by their blue color.

USB 3.0 type B

The USB 3. 0 B-type connector is found on USB 3.0 devices. This connector is designed to transfer data and power USB SuperSpeed devices. Cables with this connector are not backward compatible with USB 2.0 or USB 1.1 devices; however, USB 3.0 devices with this type of connection can connect to previous USB 2.0 and 1.1 cables.

USB 3.0 Micro B

The USB 3.0 Micro B connector is found in USB 3.0 devices. This connector is designed to transfer data and power USB SuperSpeed devices. Cables with this connector are not backward compatible with USB 2.0 or USB 1.1 devices.

Female:

Micro USB AB

Designed exclusively for USB On-The-Go devices, this versatile connector can connect to a Micro-USB A or Micro-USB B cable. This interface is easy to identify with its gray receptacle and compact 5-pin design. This type of connector exists only as a socket for On-The-Go devices, but cables with this connector do not exist.

Micro USB A

This USB-IF recognized connector can be found on newer mobile devices such as mobile phones, GPS devices, PDAs, and digital cameras. Micro-USB A is a connector that is physically smaller than USB Mini-b, but supports high data transfer rates of 480 Mbps and On-The-Go functionality. The connection is easily identified by the white socket and compact 5-pin design.

USB Mini-b (Fuji

^® )

This is another unofficial connector that is also widely used on digital cameras, especially on some Fuji® models. Because of its flat, rectangular shape, it looks more like an A-type connector.

Everything about USB-C: connector mechanics / Habr

There are two cases in which electronics engineers have to think about the mechanics of USB-C connectors. The first one is connected with the breakdown of the connector, and the second with the need to install it on your own board. In this article, we’ll cover both.

Approx. per. : Here is another part of the series about USB-C , dedicated to the mechanical features of the device of these connectors and their installation on boards. The rest are available here:

Electronics Introduction

Cable types

Connector mechanics < — You are here

Adapters outside

standard

Resistors and E-Marker

Power Supply

High speed interfaces

Notebook Framework

Soldering iron Pinecil

Sins of manufacturers

Communication via low-level protocol PD

Reply via PD protocol

▍ Connector cleaning

What if the jack on your phone or laptop started to malfunction or completely failed? First of all, the reason for this may be dust or debris that got into it. In such cases, you can use special swabs to clean the connectors. Chances are that with the help of a small amount of isopropyl alcohol or another suitable liquid, you will be able to achieve a “good enough” condition. You can also refresh the soldering of the connector contacts with a stream of hot air or with the help of a sharp soldering iron tip and flux – in case of mechanical breakdowns, this usually helps, at least for a while.

And how can a connector break in general? Alternatively, a contact may break off inside the connector housing, or dust may enter there. Imagine a device with USB-C sockets for USB 2.0 charging and data transfer, but without high-speed pairs – which, unfortunately, we see in most phones. Try connecting such a device to a USB-A charger with a USB-A to USB-C cable. Does it charge, at least slowly? If so, then everything is fine with the VBUS line.

Now plug it into your USB-C charger with a USB-C cable. In this case, the CC contacts are used. Does the device charge in both directions? If yes, then both CC contacts are in order. If charging goes only in one direction, then one of the contacts is broken. Next, you can check the USB 2.0 pins used to transfer data and charge older devices. Connect your phone to your computer with a USB-A to USB-C cable. Is it defined as a device? In both directions? If not, it is advisable to clean the D- and D+ contacts, possibly both pairs.

▍ Can sometimes replace

It is also very good if you can disassemble the device, get the USB-C socket breakout board and check the conductivity of its contacts. But what if the connector is too damaged, and some contact is not conducting, despite being soldered? This is a sad scenario, unless we are talking about a fairly popular device.

Personally, I wouldn’t be surprised that there could be thousands of different types of USB-C connectors – every laptop or phone in the world seems to use a slightly different version of it, mechanically incompatible with the others. If the USB-C connector on your expensive device stops working, you may find yourself needing to find a very rare replacement.

In addition, they are also often quite difficult to desolder and change, given that such connectors are always a combination of SMD parts and through-hole parts. Sometimes the SMD pads are right under the connector and are not accessible. And in the case of edge connectors, they are sometimes located on both sides of the board. Often there is plastic right next to or even above the contacts. All this makes it very difficult to remove the connector using hot air or a soldering iron.

It’s good that not all manufacturers design their devices so ill-conceived. The USB-C connectors on the new MacBooks are located on separate, easily removable parts. In many phones, the USB-C port is located on a separate small circuit board. In both cases, you can simply buy a replacement board and install it without any problems to replace the non-working one. It is clear that disassembling modern phones is a troublesome process, but I think you can be grateful even for the fact that they provide at least some convenience.

A cotton swab probably won’t help. But you can easily measure conductivity

By analogy with MicroUSB, USB-C connectors usually have small latches located inside on the sides. Naturally, as in MicroUSB, these latches also wear out. Fortunately, this is solved by simply buying another cable. But what if it’s your favorite cable, or you want to build your own?

You can also buy USB-C connectors with small breakout boards that you can solder wires to. These connectors allow you to create your own cables. Personally, I buy them from LCSC, because this resource has a wide variety if you know where to look. There are connectors with pull-up resistors that are great for assembling USB-A to USB-C cables, but for the USB-C to USB-C variant, it is better to remove the resistors. There are also plugs on which both SS pads are presented, which is very convenient in case of assembling your own extension cords or something like that. In addition, on this resource you can find connectors with programmed E-Marker chips – in case you want to get 5V from the PSU, and you, among other things, need to assemble a custom cable.

Well, since we have already started talking about assembling our own solutions, let’s look at how to do it correctly – again, confining ourselves to the mechanical aspects of the matter.

▍ General rules for connectors

First you need to pay attention to the positive features of USB-C connectors. The vast majority of them contain through-hole pins – a welcome innovation since the old MicroUSB and MiniUSB, in which the cheapest connectors were surface-mounted only, as a result of which the connector could easily be ripped off the board. Finding an all-surface-mount USB-C plug is really hard, which makes them mechanically more reliable.

For electronics engineers, this somewhat increases the cost of creating printed circuit boards and general assembly. You need your chosen manufacturer to be able to cut the PCBs as they are required for most USB-C connectors, and if you order a pre-assembled PCB, you get two or four additional through-hole pins that require manual soldering, which incurs additional costs . However, this is definitely for the best, and prices will come down over time.

USB-C connectors have their own current rating. It is supposed that they should have 5A, but I came across Chinese products with a rating of only 3A. Here you need to look at the technical data sheet of the part. Naturally, if you install a connector with 5A support on the board, then remember that it will transfer these 5A only if the board requests them, which, in turn, requires communication via USB using the PD protocol – the usual double pull-up with 5. 1kΩ resistors for This is not enough. The good thing is that if you are not going to make a connector specifically for 5A, then you do not need to check the rating.

Cons: Very small vias must be used to route this circuit. Plus: it looks like it’s ready to eat you (photo from RealTimeKodi)

The reason for such a variety of USB-C connectors is that there are so many ways to place them – on top of the board horizontally or vertically; vertically, pointing to the side; flush with the board at different heights; well, just using products of different quality. There are also a huge number of options for outputting high-speed pairs if you need them in the connector. Some use SMD pads for high speeds, while others use through-hole mounting. And all this is just the tip of the iceberg.

However, not every connector will suit you, which somewhat limits such a huge variability. First, you will find connectors without CC pins that will only work with USB-A to USB-C cables. It can be assumed that such connectors can be used in cheap soldering kits for beginners. Although such in any case should not be used. There are also many connectors in which the SMD solder pads are completely hidden. And if your skill in applying solder paste through stencils is not high enough, then fixing soldering problems on such connectors will be very problematic.

▍ Low speed – simple rules

Custom USB-C trigger board with PD support and time-tested 16-pin connector based on Ch324K chip

Suggest limited to USB 2.0, CC and of course same, VBUS and GND. As an optimal proven connector, electronics engineers usually take the 16-pin SMD version. It can be found on development boards, cheap USB-C products, and in many homemade products – the peculiarity of this connector is that it is in some way defined in the USB-C specification. In KiCad, its footprint is represented as USB_C_Receptacle_HRO_TYPE-C-31-M-12 with the corresponding symbol USB_C_Receptacle_USB2. 0 , but HRO is clearly not the first to develop this connector, and there are many analogs that are compatible with it in pinout and footprint. Also, as mentioned, here you will have SBU lines that can be used for something like a UART. You can also remove these SBU pads from the footprint, as shown in the photo, to eliminate two extra pins that can be accidentally shorted when soldering.

When you find a nice alternative connector, be sure to match its pin numbering from the data sheet with the numbering on the PCB footprint diagram. There were cases when these numbers in the passport differed from the typical ones, or it was misleading, leading to errors and subsequent many hours of corrections after problems were discovered. When reading the technical data sheet, also pay attention to whether it indicates the recommended board thickness for installing such a connector. Although they are installed on top of the board, its thickness can determine the difficulty of soldering contacts. But this is more of a recommendation than a requirement.

Fluff M0 board [deshipu]

Naturally, you should not be afraid to look for and use any desired connectors. For example, if you don’t need USB 2.0 and would like less soldering problems, then there are very good options that only have GND, VBUS and CC pins. As a rule, if you need a connector that is exactly suitable for your case, then you will always find one, and as a proven option, you can keep in mind the very 16-pin one that was written about above. Oh yeah, if you’re using a 0.8mm board and want to save a lot, you can embed the connector right into it. It may not turn out very beautifully, and in the end it may let you down, but still it should work quite well for a while.

▍ High speed – high demands

What if you suddenly need connectors with access to high-speed lines? Unfortunately, in this case, I will not recommend a specific model, but I can give some advice.

For when you don’t need to be able to control your soldering at all (photo from Cyber City Circuits)

soldering. You can also find a few connectors that you think are suitable, order samples, design a board with test footprints for them, then try to build a few and see how it goes.

If you find an online diagram of a footprint that seems to fit the selected connector, carefully compare and double-check the dimensions – even if the name of this diagram exactly matches the connector number. Two months ago, I decided to assemble a breakout board that carries all the high-speed lanes for a USB-C connector so that the signals at least look like a differential pair. It is not particularly suitable for everyday use as USB3 or DisplayPort as I ordered it as a dual layer board and its impedance is inaccurate. However, this option is still better than conventional breakout boards, on which “high-speed” tracks turn under 90°.

I found a schematic of a footprint in KiCad that seemed convenient for soldering – it suggested through-mounting a number of contacts under the case and there were sites for surface mounting of a number of contacts outside the case with the ability to crawl with a soldering iron. At LCSC, I picked up several connectors that should have fit this scheme. When it came time to solder them, it turned out that the screen contacts in the front were displaced by a few millimeters from the seats. In addition, the holes in the PCB for through-wiring after coating turned out to be slightly small – in the next version I will definitely make them larger.

▍ End-mount connectors

You may well find an interesting edge connector with internal high-speed pins for through-wiring. In this case, when designing the board layout, you may find it impossible to output the two deepest signals – one CC and one SBU. Alternatively, you can omit these pins if the footprint is intended for a USB-C plug – in this case you are not using SBU and you do not need a second pin for VCONN, which, in fact, is an unused CC pin used as power for E Marker.

But it is possible to solve this problem. The first way is to use a multi-layer board and bring the contact through the inner layer, where there are no ring through pins. The second method involves using traces small enough to wrap around the connector at the edge of the board. There is also a third option where you can reduce the width of the two through-hole pads around the top layer’s two pins of interest to fit a trace between them.

Connectors on Payload Implementation Board for Nintendo Switch

Most of what I have mentioned applies equally to connectors and plugs. Naturally, there are features characteristic of the connectors. For example, there are mid-wire connectors that carry the entire set of contacts distributed on two sides of the board. By the way, soldering these is very convenient. On the other hand, I have no idea how such connectors are soldered at the factory. Judging by the devices I have disassembled, the method of reflow is used for this, and not manual soldering. But since the SMD pads that the connector attaches to are on both sides, it’s not clear to me how a stencil can be applied to such a board, especially in a large-scale production environment.