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Industrial TI Tech Days 2020
Industrial TI Tech Days - Power management sessions Understanding USB Type-C connectors and USB Power Delivery to maximize industrial designs
Industrial TI Tech Days 2020
1.1 Understanding USB Type-C connectors and USB Power Delivery to maximize industrial designs
Welcome to industrial TI Tech Day. This is the Understanding the Type-C Connector and USB Power Delivery session being presented by Adam McGaffin. My name is Eric Beljaars And I'll be the moderator for the session. All participants are muted for the session. Please use the chat function to ask a question and address it to everyone. Also chat if you're having any problems hearing or seeing the presentation. With that, I'll hand it off to Adam to get started.
Great Thanks for the introduction. So yeah, so today we'll be talking about understanding USB Type-C and USB Type-C PD. The agenda can be broken down into three different categories. The first one, we'll go over just the general introduction into USB Type-C, and power delivery, and how those are actually different from one another, and understanding those concepts at a high level.
Next, we'll go over some Type-C PD battery charging reference designs that we would like to highlight. And then the third, we'll go over our portfolio and how it can be categorized as well as the value propositions for some of our key products. So first we'll be going into just the general introduction of Type-C and Type C PD.
So first, just giving the history of USB connectors and what is Type-C. So you can look on the left, just from a history standpoint of what USB Type 2 to USB2.0 and USB3.0 connectors look like I'm sure we've all seen these before. And then on the right, of course, is the Type-C port. And so it's a reversible and bidirectional port. But it is not a new data standard.
It just incorporates the USB2 data, USB3, and then, once you get into Type-C PD, you can then incorporate alternate modes like display port as well as power delivery from a high voltage application. And so you can see in that image to the right with a Type-C PD application, you can incorporate power and data, both USB 2 and 3 video as well as audio all into a single port.
And so what is USB Type-C and Type-C PD? So USB Type-C is in reference to the physical interface. So the Type-C port itself and Type-C PD is in reference to the specification that can be done over Type-C. And so not all Type-C applications are going to be Type-C PD, but all Type-C PD applications are going to be done over a Type-C connector.
And so thinking of when to use Type-C, you can see that they're kind of a ton of different applications. And so for a standard USB Type-C application that can pretty much be anything that currently uses Type-A right now. So just a USB2 or USB3 data and only 5 volts of charging and no alternate modes can be done using just standard Type-C.
And then, when you need Type-C PD is when you want to do alternate modes, such as display board or charge higher than 15 watts. So Type-C PD allows for the ability to charge either source or sync current up to 100 watts.
Next slide-- and so this slide kind of shows how Type-C in itself is just a physical interface. It's not introducing a new form of data structure. It just supports the ability to have USB2, USB3, or display port all on the same Type-C receptacle. And so the top and bottom kind of show two different applications that you can have on the same port, just depending on what your needs are.
So the top graphic is a USB-only application. So you only care about USB2 or USB3 data, and you don't care about any type of alternate mode, nor do you care about high voltage charging. And so in this type of application, you would only need a CC controller.
And we'll go over, in a separate slide, the physical interface of the Type-C port in the role that the CC pins have. But all you need is some type of CC port controller to present a pull up resistor or pull down resistor, depending on if it's a source or sync.
And then it would then connect-- or using a USB3 application, you would then have this CC controller connected to the MUX switch redriver or whatever the application calls for to route the correct USB3 lines to the relevant Type-C pins. And we'll kind of go over that pin out in a later slide. And then same thing for the other ends. You would still need that CC controller MUX switch redriver to pass-- to once it's receiving that USB3 data, to pass it through.
And then for the second application, shown here below, it's the same physical pin-out as above. It's just the system requirements are different. And so in this example, we're saying it's going to have the ability to do all modes, such as DP. And so through Type-C and Type-C PD, you can have USB2, USB3, and Alt modes all coexisting next to one another.
And so this is done, so once you establish the fact that you want a PD controller-- or once a Alt mode application, you then need a PD controller. And the role that the PD controller has is to negotiate. So this one system negotiates with the other system.
The PD controllers negotiate between one another indicating that it is a Alt mode capable system and then that it would then want to go into DP Alt mode. And same with the USB-only application. You're going to need some type of MUX redriver switch to pass through the relevant USB or DP signals. And then, of course, [INAUDIBLE] back from source to sync.
And so this slide shows just kind of the history of power over USB. And so from a standard type A, like a non-Type-C port application, the most it could do-- or still can do-- is 7.5 watts. And that's through the use of USB BC 1.2.
And then Type-C came along. And it allows users to go up to 15 watts or 7.5 watts at 1.5 and 3 amps respectively. And then with the USB PV, you can have the ability to charge source current up to 20 volts and up to 5 amps. So you have the ability to source or sink 100 watts bidirectionally to the use of a single port.
And then this graph shows just the history of USB data speeds. So USB 2, 0.48 gigabits per second. And then [? it ?] [? can ?] [? go ?] [? up ?] with USB 3 and 3.2. And then with the most recent of USB 4, once again, you're going to need some type of Thunderbolt controller and the most recent Intel device. But you can go up to 40 gigabits per second.
So this is the physical pinout of the Type-C port. So you can of course see that it can be categorized with your ground connections. And then you're going to have your two superspeed or high-speed data connections. And so this is how you can have, depending on your application-- so say you want to just do DP two-line. So you can have DP taking up one set of the superspeed lines, and then your standard USB 3 data picking up the other. Or you can have DP four-lane where it takes up all of the superspeed lines.
But you can see how-- so if you think of this being the top, if you were then to reverse this TX1 would then be down over here. And TX2 would of course be over here. So this is why you need some type of mux to route the correct superspeed pins accordingly depending on the polarity of the connector. And the polarity is determined through the use of the CC pins, the configuration channels. So there's going to be two of them.
And depending on the connection of both of these, the PD controller can then determine the orientation of the cable connected to its relevant Type-C port. And this configuration channel is also where all of the PD negotiation is done as well. So it kind of serves three purposes of determining the orientation, acting as the main channel for negotiation from the PD perspective, as well as supplying VCONN for an active cable.
And then we'll go over in a second how a PD message looks and the structure of it. And then you have your USB 2 data, which these can be shorted together, or use the mux as well. I've seen both. And then your SD lines, which the auxiliary pins are only needed for DP. You don't need these for just standard USB.
OK, so next we'll kind of go over, just high-level, a typical flow of Type-C PD. So you'll first start with a default of 5 volts. And that's determined by the pull up resistor value of the source. And so once RP and RD are negotiated, 5 volts will be presented on the VBUS. And then, from there, the power delivery negotiation occurs over the CC channels. And then once that power negotiation occurs and a high voltage is negotiated between the two, and power's supplied over VBUS at the rate negotiated. So in this example it's 20 volts.
One other thing to point out from this slide that we haven't talked about yet is the role of-- or I guess the terms DFP, UFP, and then as well as source and sink. So one thing to point out is that, with standard Type-C, the data role-- so DFP and UFP. So DFP stands for Downstream Facing Port. So you're supplying the data. And UFP stands for Upstream Facing Port. You're receiving the data. With standard Type-C, these are strictly tied to the power capabilities of that given connector.
So for example, if you're a standard Type-C source, you're going to be a DFP. And if you're a standard Type-C sink, you're going to be a UFP. Those terms are directly tied to one another. However, with USB Type-C PD, you have the ability to do data role swaps or power role swaps. So these terms are not tied to one another directly.
So for example, you can be a source UFP or a sink VFP. An example of this is think of a dock and a laptop. So that dock is going to be wanting to provide power to that laptop. So it's going to be a source. But it's going to be wanting to receive the data from that laptop. So it'll be a source UFP. And then inversely, with the laptop, it's going to be receiving power from that dock. So it's going to be acting as a sink. But it's going to be sending its USB DP, whatever data it is, it's going to be sending that to the dock. So it's going to be acting as a DFP, so a sink DFP. And that can only be done using Type-C PD.
OK, so next we'll kind of go over what exactly is an alternate mode. And the example we'll show is a display port. So before Type-C, your traditional mode of operation of connecting a USB device, a charger, as well as some type of video sink is you had to have a separate connection for all three. So you'll connect a USB Type-A connection to your USB cable, some type of DP or HDMI connection to your connected sink, and then your power adapter accordingly. So you kind of need those three different connections.
But with USB-C, you can have that one connection for the USB Type-C port, have that be both your USB and DP connection. So in this instance we have dock or a USB hub connected to the laptop from USB-C to USB-C. And then this dock itself will negotiate an alternate mode between itself and the laptop, and then pass through the USB data and the DP data accordingly.
And then another example that we've seen is you can also have some monitors act as a power source and a video sync. And so this is kind of another example of how the power role doesn't have to be tied to the data role. So in this application it'd be source UFP and sink DFP. So when you read the term, alternate mode, this is what it's in reference to, the ability to enter into an alternate mode such as display port for video and such.
OK, so how it works. Just let me go through. So negotiating power is simple. And it can be considered robust. Step one is that the source just sends its capabilities. And then, based on those capabilities, the sink makes its relevant request. And in the next slide, we'll kind of show a PD message of how this actually looks. And then once that negotiation between the two is done, the source accepts that request and then sends what's called a PS_Ready message, pretty much meaning that it's ready to start supplying the new negotiated contracts, that they've accepted the contract and go from there accordingly.
What happens when sink needs more power? So the sink can send what's called a capability mismatch, indicating that it actually needs more power. And then, from there, the source would then read the sink's capabilities and determine how much it needs to function.
And then another thing that can be also supported is the exchange of extended capabilities. And these can vary for PD3 applications. But the source can share its overload. Peak current capabilities, the sink can share its specific load characteristics. The sink can also share its relevant battery information. There's kind of a lot of different extended capabilities that can be sent and received other than just the source and sink capabilities.
OK, so this kind of shows a typical startup sequence for USB Type-C and PD, just from a visual point of view. So step one is, once you connect those two devices to one another, the first thing that the PD controller is going to do is determine a valid RP and RD. And so this is on the configuration channel, the CC pins. The source is going to be presenting its pullup resistor. The sink is going to be presenting its pulldown resistor. And it's going to be trying to detect that valid connection between the two.
And then once it's detected that, the source is going to provide 5 volts at 500 milligrams. And then depending on if it's a PD device or just a legacy device, using a Type-C cable, it'll either move on to BC 1.2, which has its own negotiation protocol, or it'll go into PD. And so for this conversation, we'll just stick strictly to the PD portion of it. So it'll establish a TV contract.
So going back to the previous slide, sending its source capabilities. And then the sink choosing one of those source capabilities. And then the source would then provide the negotiated power. And then once you have that negotiated power sequence, you can then move on to alternate mode if it's configured for that. And then once the alternate mode, such as display port, has been entered in, you would then begin the USB enumeration process from a D-plus/D-minus perspective. And then you would continue on to any other CC negotiation that's needed.
OK, so this is just kind of a quick overview of taking everything we just learned and looking at it in a real-world application. So the left is an oscilloscope capture of VBUS in yellow, PPHV in green. And when we say PPHV, that means the system voltage. And so there's going to be some type of switch, either it being a load switch, back-to-back insets. There's going to be some type of isolation between VBUS and PPHV. And so this is the VBUS on the Type-C connector and PPHV is that system voltage that would then be passed through from VBUS. And then you have CC1 and CC2 down below.
And so you can see that we start off in 0 volts for all four connections. So there's nothing connected. And then as soon as we connect that Type-C port, you can see CTC goes high. So it's presenting its RP and RD respectively. And 5 volts is presenting on VBUS.
And how this system is set up-- and so why you don't see PPHV also go to 5 volts is that this system was set up to where it wouldn't enable that isolation circuitry until VBUS started receiving 20 volts. But we'll get to that in a second.
So 5 volts is on VBUS. And that kind of ends the implicit portion of the Type-C [? contract. ?] It can then move over to the Type-C PD portion, which starts with the power negotiation.
And so then if you look on the right, this is using a Type-C PD analyzer. There are a ton on the market. But they all share the same purpose of deciphering the PD messages that are sent between the two devices. So it negotiates the 20 volts. And then VBUS goes to 20 volts. And then PPHV rises to 20 as well. And then here you can see the alternate mode is negotiated accordingly.
OK, so next we'll go over the battery charger reference design that we'd like to highlight. We talked about this at the beginning, but just wanted to touch on it real quick again, just mainly the fact of Type-C PD being adopted in a wide variety of different markets other than laptops, monitors, and docs.
We're seeing it being adopted in power tools, wall plugs, avionics, wireless speakers, a wide variety of different applications, one being the fact that a lot of them are using it as a barrel jack replacement with the understanding that, with a wide variety of different applications all using Type-C, an end customer will have their own Type-C charger. And so there would be no need for a customer to develop their own proprietary barrel jack charger when they can just throw a Type-C PD application on it and have the consumer use their own charger.
So before we go into the charger reference designs themselves, I want to highlight the solutions that will be showcased from a battery charger perspective. It uses the BQ25790 and 792, as well as the BQ25730 and 731. And we'll go over the differences between these two. But at a high level, 790 can support 4S and has integrated power FETs. The 730 and 731 can do up to five-cell applications and does not include those integrated FETs. And then from a Type-C PD controller perspective, I will be showing the TPS25750S and 750D. And we'll go over the differences and similarities between those two.
So from an optimization point of view, the pairing between the 750D and the 25790 is going to be the most optimized charging solution for a four-cell battery up to 45 watts. And so you can see that the 25750D integrates a high-voltage bidirectional power path, which will then connect to VBUS and pass that through to the battery charger. And within the battery charger, it integrates its four power FETs with the need of only an external inductor. And then pass that voltage through either to the system or battery accordingly, supplying the system or the battery depending on how it's configured.
And as far as connecting to the battery charger itself, the PD controller, through the use of our online GUI tool-- we refer to it as a GUI vending machine. And you can pretty much go on, fill out your system requirements from a power perspective, if you're using a battery charger, the specific battery charger you're using, the characteristics of the battery itself, just all of these different variables.
You put it in. The GUI tool would then generate its own binary that would be flashed onto the PD controller. And then, from there, the PD controller will control the battery charger itself.
And so if all you care about is the charging of your battery and the passing through of power to the system, and for it to be static, the PD controller can handle it all. And then if you want to have additional capabilities, you can also connect a MCU for additional features. But that's by no means required. This can be its own isolated system where the PD controller controls the battery charger directly.
And then for five-cell applications, highlighted the 750S and the BQ25731. So the 750S is real similar to the 750D, the only difference being that the S, instead of having that integrated bidirectional power path, it has the ability to control two back-to-back insets through the use of built-in gate drivers. If you and your system care about picking your own FETs, then this is an option as well.
And then it would pass it through to the battery charger. The difference being, with the BQ25731, of course it's supported up to the five-cell applications. But it has the external FETs. Reason being is that it can support a higher wattage of 200 watts as well. But the same general application applies to both this solution as well as the previous, from the perspective of the PD controller can control this battery charger on its own.
So you would still use the same GUI tool. You would just put in the fact that you're using 750S and the BQ25731, put in all of your other relevant parameters. The GUI would output its relevant binary, flash that to the PD controller. And then the PD controller will control the battery charger based on your parameters.
And it can all be, once again, its own isolated system. But if you choose to have other advanced features you can of course connect your own EC for that.
So then highlighting the integrated versus non-integrated solutions-- so the pairing of the 750D with the BQ27592 is by far the most integrated solution that we have. There's no need for external FETs, as it pulls in seven total FETs, so two for the PD power path, and then four for the high-side and low-side switches, and then one for the battery FET. All of those are pulled into both of these relevant PD controllers.
And then with the 750D having the ability to control the battery charger, there's no need for an external MCU either. Once again, you can have that if you want additional functionality, but it's by no means required. And the PD controller can control the battery charger on its own. And so that would effectively cut out that entire block.
And then finally, as I mentioned before, it's configured using a simple web-based GUI. You don't have to know all the finite details required for a Type-C PD application. You can go in, fill out, and check the relevant questions within the GUI tool. And it'll output its relevant file. And then the PD controller will handle the rest from a Type-C PD negotiation as well as a battery charging perspective.
And then additional information on this-- so Eric wrote a good technical article. And all of these slides are going to be shared online after the fact. But more can be read online from [INAUDIBLE].
OK, so final section. And we'll end off with just a quick portfolio walkthrough showing the different categories that our devices can be categorized into, and then the value propositions of some of those.
So from a just broad portfolio perspective, our devices can be categorized into the following three categories. USB Type A on the left. So for just your standard Type-A source receptacle-- laptop, powerbank, wall charger. It can be either power-only or with data. It can be categorized into that left common.
Your standard Type-C application-- so only care about charging at up to 15 watts. And you only need USB data. Can be categorized under this middle category in the Type C PD, with the ability of doing alternate modes.
Power and data can be categorized in the far right. And so in each one of them have their own relevant applications.
OK, so kind of touched on it in the battery charger reference design. But I'll go into a little bit more detail here. So this 25750D is a single USB Type-C dual-role port USB PD controller. And there's a lot of different features enabled within this PD controller, some of them highlighted accordingly.
So we'll start with the integrated 5-amp bidirectional power path. And so this was, in the example of the battery charger connected directly to the input of that battery charger. And so through this power path, it can be either configured as a sink, a source, or both, depending on your system needs. So going back to the battery charger, if you want to charge the battery but also source power from that battery, that all can be done through this single integrated bidirectional set.
It also integrates a dedicated 5-volt source power path. So if you're, let's say, in an application where you only want to be a high-voltage sink and a 5-volt source, you can set that up accordingly through the use of this integrated high-voltage power path being your 100-watt sink path, and then this 5-volt source path only providing the 15 watts that maybe your system [? needs. ?]
And then it also implements comprehensive power path protection by having 28-volt tolerance on the VBUS pins as well as a 26-volt tolerance on the CC pins in the event of a potential CC short to VBUS.
Talked about this earlier-- the ability to control a battery charger via I2C, and all of that being done through the binary vending machine GUI as we like to call it.
So comparing the 25750D to some of the competition-- so we'll just, I guess, look on the right, of how some applications need a lot of different ICs to control some of the base functionality. So in some applications, you will need your own external power path, your own 5-volt power path, the dead battery LDO, VCONN power path for on the relevant CC pin, the own PD negotiation that's going to be needed for the CC pins, so the PD modem, I2C, and then VC 1.2 charging if that's what your system-- if you would like to have legacy charging as well.
The TPS 25750D is able to pull in all of those separate blocks into a single device from a smaller solution size, as well as just ease of use [INAUDIBLE]. You just have to be worried about this one PD controller. And it handles everything on its own. The only thing that is needed. In addition to this is an external I2C EEPROM for storing of the configuration.
OK, next we'll go over 25750S. So very similar to the 25750D, the only difference being the power path. So with the 750S, it does not integrate that high-voltage bidirectional power path. But it does give you the ability to control two back-to-back insets through the use of built-in gate drivers. So if you or your customer wish to control the sets that are placed on your system, you can, of course, use the 750S application and have that PD controller drive those relevant insets accordingly.
Same thing with the 750D-- comprehensive power-path protection so that VBUS and CC tolerance is the same, 28 volts and 26 volts, respectively. I2C control to the battery charger is the same. And then you would also use the same GUI. And so everything is the same except for the back-to-back insets, if that's what you prefer to choose for your relevant application.
And then, similar to 750D, the TPS25750S, when compared to the competition, is able to pull in all of the blocks to the right, excluding the external power path, but can be controlled using the built-in gate drivers. But it also needs the I2C EEPROM as well for firmware loading.
But also one thing to note, though, is that even though this is an external power path, the TPS25750S incorporates the same amount of protection that's included with the 750D for that internal power path. So it still is able to do RCP-- so Reverse Current Protection, overvoltage protection, and overcurrent protection. So even though it's an external power path, it still has those protection features that are needed for a majority of systems.
OK, so finally showing just the general overview of some of the hero products for the different categories of applications. So for USB Type-A, it's either the TPS2547 or TPS2511, depending on if you're wanting to do data or not. They're only one-port control. There's the TPS25810 is our standard USB Type-C application that includes its own power path. There's a single-port controller that has its own internal power path.
The TPS65987D and TPS25750, these are some of the nonindustrial PD controllers. We went over the 25750. The difference with the TPS65987DH is that it includes two bidirectional high-voltage power paths for a slightly larger [INAUDIBLE] size.
For industrial applications, we have the TPS65994. It's very similar to both of these previous PD controllers, the only difference being that it's a dual-port PD controller. So it can control two standalone Type-C PD ports.
And then TPD6S is our protection device. So it's our Type-C protection device. So in the event of short to VBUS, ESD, just general protection that customers may require on their Type-C port, the TPD6S300A is the protection device to go with.
And then these last two devices are the load switches we have that can be paired with our PD controllers or competitor PD controllers to enable the use of that external power path.
And so that is the end of the presentation. So do we want to open it up for questions? Or were there any questions that came in, Eric?
That should be it. So thanks, Adam. And thank you to everyone for joining us. All session recordings and presentations will be available to view and download next week. You will receive an email with links to the on-demand presentation and a post-event survey. We would like your feedback so we can continue to improve our content for future tech days and other training events. Thank you again. And have a great rest of your day.
2020年 11月 5日
This presentation will provide a high-level overview of these technologies and their benefits. It will also be cover the applications covered by TI's current portfolio and the technical challenges that they may pose from an integration stand point.