IGBT and SiC Isolated Gate Drivers New Product Announcement
[CHIMING] Welcome, everyone. My name is [? Nagarad ?] [? Anshreeter. ?] I'm the Marketing Manager in the High Power Gate Drivers Business, in Texas Instruments Gate Driver Business. The title of this presentation is IGBT and Silicon Carbide Isolated Gate Drivers. So what we are going to talk about today is industrial applications where isolated drivers could be of a key enabler towards improving efficiency and reliability.
So first off, before I go into the drivers, let me kind of spike out a few things. The main thing that we need to look at is, what are the trends that's driving change in power management? So there are-- I spike out five things, primarily, which is low EMI, power density, low Iq, low noise, and isolation.
Now, there are a few things that spike out when it comes to isolated drivers, which is power density and isolation. And maybe the third one I could also add, low noise is a key factor as well.
So power density people in the power management world typically think-- they think about, how do I integrate everything, make it small in size, but yet get a high efficiency? That's the underlying goal of power density.
The second thing would be isolation. So power management doesn't mean that we are just talking about transferring power, let's say, in your cell phone when you are using it. But it also-- we are talking about power, offline power, which is power from the wall which is high voltage. It could be power from the solar panels, which is high voltage. Power from your car battery for an electric vehicle, that's high voltage.
So that voltage is high voltage. So anything-- typically, usually around greater than 50 volts is considered high voltage. But the high voltage I'm talking about here is even extensively beyond 50 volts. So it's not just the power transfer, but also the voltage that's of significance.
So it's very important that when humans or when any other communication peripherals or any intelligence systems are interacting with such ecosystems, it's very important to make sure that there is some kind of a barrier that has all these issues that it's isolated from. In other words, you want the isolation to kind of give you the high voltage in a separate ground, versus going on at the load, and that's kind of what the underlying factor is about isolation.
So with that being said, let me kind of now jump into the key features of an isolated driver, so that kind of puts all these things together. So main thing, as I said, you're going to see the two key focus areas in trends that's going to be part of the key requirements for an isolated driver.
First is the high working voltage. What that means is the driver needs to handle any high bus voltage such as could be a 400 volt, 600 volt, or 1,500 volt. These are typically coming from applications that's having those kind of voltage input requirements, and even-- perhaps even output. So the driver needs to handle at least beyond that, well, that voltage. So that's the working voltage.
Second thing is that drive strength. So a driver is something, fundamentally, that's a device that takes all the signals from a controller and turns on or off a power device. And the whole idea is that if you think about a power system, it's basically a topology, and that topology is essentially transferring power from the input to the power output, ideally at 100% efficiency. Right?
So but to do that, your controller doesn't have enough, I would say, ability to kind of turn on and off these powers switches. Because it's very important that these switches be able to be on or off at the highest capacity. Whole idea is you don't want any losses coming out of these power switches, so that's why it's important to operate at the right voltages. And to do that, all these-- most of these power switches have built in capacitance.
So you need to have enough drive strength to turn on and off these switches, so that's the key thing. So which is why drive strength or the drive current in a driver is extremely important to allow for that, which means you need to quickly turn on and off. That's why I have this extra factor called propagation delay, rise time, for all times.
The third thing would be the high immunity, and this is something that it's part of an isolation requirement. You need to have high power protection, surge protection, like 12.8 kV.
Then you need to even look at any noise immunity. And that's typically if you have any false input data which is typically coming from noise and that is typically high frequency, and so that means your voltage, rate of change of voltage, could be pretty high. So you need to make sure you're able to withstand that. That's why 100 volt per nanosecond is very important. And this is typically becoming important in industrial application as people are going towards wide bandgap applications such as silicon carbide.
And the last thing is the high power density that I talked about. So, in essence, if I kind of look at now-- take a step back and now look at the power devices and the power management systems. Typically, all these topologies would use one of these three in high power industrial systems.
First one would be the traditional MOSFET, silicon MOSFET, typically used in voltage ratings below 600 volts. Most of the applications would be for power supplies. And the main thing is that the advantage of using MOSFETs is because it can switch really fast.
Now, silicon IGBT, that's typically used in very high power industrial systems such as motor drives. Could be-- like such as AC drives and CNCs. Could be for large solar inverters, like a solar farm, where driving switching frequencies not of essence. Because size is not of key importance, although it is becoming important in some applications, especially in some of the robotics applications.
But so that's why these are-- I mean, you take advantage of IGBT. It can withstand much higher voltages and have much lower conduction losses and, therefore, you can use them in these kind of systems.
Now, silicon carbide is kind of taking the best out of both. It can switch really fast. It can withstand very high voltages. So it gets-- it's basically now competing with silicon or IGBT applications. And it also, pretty much, can compete with silicon MOSFETs because they switch really fast. And so you get the best out of both. High-- I mean low switching frequency-- I mean low conduction losses, low switching losses.
So you take that, and then you kind of put all this into all these applications, so it pretty much goes a lot into primarily, right now, today, into motor drives, solar. And then in automotive, it's heavily into the traction or the HEV EV powertrain platforms.
So now, what I'm going to do is start showing you what TI's isolated gate driver portfolio looks like. So I know it's a crowded chart. Don't need to spend too much time, but what I want to kind of spike out is the following. If you look at this slide, on the left side, you have two sub-buckets. I call it as basic and reinforced.
Basic is something that is an isolation requirement based on some certifications that kind of tells you where the driver needs to be. So essentially, all drivers or any of the devices that requires isolation needs to go through a certification. So that certification would kind of entail what that would be. Would it look like a basic or reinforced?
Reinforced is a much higher level that can withstand much higher voltages, so that's fundamentally what that means. And some applications don't need reinforced. Some just need basic. So I'm just kind of bucketizing that into two different areas and isolation.
Now, having said this, typically you'll have drivers which are a single-channel or dual-channel. So what you're seeing here is there on the top left corner, and you'll see a lot of single-channel drivers. Some of them are simple, and some of them are complex.
So simple drivers are the ones right in the center where it's like, all you have, all the functionality is primarily an input in an output that kind of gives you the what other drive strength it is and that can go up to certain voltages. And these voltages are dependent on the power switch. And also, that is a particular UVLO. We just call the minimum voltage at which it can turn on. You don't want your voltage to be too low because you'll have a lot of conduction losses.
And then you have some of the other complicated drivers which are actually drivers not just doing the drive functionality, but also adds diagnostics. And we will talk about that today in detail in one of these parts.
And then the top right is what is called a dual channel, and this is actually a half bridge or dual low side or dual high side driver that can be a little bit more multifunctional, but not necessarily in diagnostics. And we'll talk about that. And these are very popular drivers in a lot of power supplies and lot of lower power motor drives, perhaps, but certainly in automotive, like onboard chargers and DC/DC converters.
And then at the bottom, you have some similar ones which is more basic isolation, very similar to this, except that it's basic. And here, it's also very similar to this, except that it's more basic isolation.
So that being said, now, let's-- what I'm going to do today is talk-- spike out two drivers that just that TI just has-- oops, sorry-- yeah, TI just released. One of them has been press released. It's not completely released to the market. The other one is completely released to the market.
So the two drivers that I'll talk to is this one, the UCC217XX, that got a press release last month, right, just before APEC, which is a pretty big conference for power management. And then the other one is the 21530, which just got released a couple of weeks back. And I'll talk about both of them today at length.
So if you were to--, if I were to jump into the first one, the 217XX family, fundamentally, as I said, this is a driver that is going after advanced performance and reliability. What that means is it's a single-channel isolated driver which has some built-in sensing, and it's really fast. And the whole idea is that you want to catch this really fast. And the whole-- and the main reason is that it's going to be-- this is a driver that drives not only IGBTs, but silicon carbide.
And as I said, silicon carbide has a much higher switching frequency, and so the time to catch any event, that it's undesirable, needs to be very short. So that's why that sensing needs to be quick. So the whole idea is, by doing that, you improve the reliability and performance and you, therefore, protect these high voltage systems.
That's fine, and this driver is a little unique because, if you kind of look at it, it offers three main benefits, and one is the enhanced system performance. And what that means is, if you look at the drive strength for this port, it is 10 amps. And that's typically very high for drivers, and it's not very easy to even build that, so the whole idea is if you have 10 amps, you can improve your switching behavior really and therefore reduce your switching losses.
Secondly, it has a very fast current or current detection. As I said, you want to catch the problem real quickly, especially when it comes to systems using silicon carbide power devices. So because it's so fast in catching the problem, it enables a fast system protection.
The second one is the system level reliability. These drivers that I talked about uses TI's capacitive isolation technology that I will touch upon at the end. So this technology that TI offers gives you the highest level of surge immunity up to 12.8 kV. And then it also has the highest working voltages that I talked about earlier.
The third one is the side the reduced system size. Now, this family has the competence that typically exists outside of the driver and, therefore, it actually adds to the system cost and increases the volt space. As I said, power density is important, so you want to try to have everything compact and small. And this guy will actually take all these solutions, integrate it into the driver, and therefore you come up with a solution which is neat and compact and therefore a reduced system size.
So the key things that we offer in terms of integration would be the buffers, which is typically sitting outside to improve your overall drive strength because it is [? tandem. ?] You don't need that. And then it has the sensors that provide much accurate temperature, current, and voltage sensing. And along with something called a unique technique called isolated analog-to-pulse with the modulation sensing. So that's the main benefit of this family.
Now, the markets that we typically cater to are threefold. One is automotive, which has more traction and onboard chargers. But in industrial, you look at it-- this part is being accepted in a lot of these solar inverters. And industrial motor drives, primarily like, as I said, you can see that like there is a big robotics, CNCs, servers, and AC drives.
So and the main benefit people look at when they look at this part, they say, aha, it gives you the advanced monitoring, fine protection and, therefore, it improves my system efficiency. So that's the main thing that we offer out there.
So here is an example of a motor drive application. So typically, where do you see in a motor drive? What do you see in a motor drive? It's typically like a three-phase inverter system that you normally-- you would see. And you can see, right here, that you have the three legs of a three-phase inverter system.
And typically in this case, I just [INAUDIBLE] it back in an IGBT module. And this module would need to be driven by one high side driver and a low side driver. So if I take these, this family of drivers, like 217XX, you basically-- you, well, by doing this, you are now improving the design challenge of getting [INAUDIBLE] the noisy and harsh environment much calmer because your CMTI rating for this driver is 150 volt per nanosecond.
Efficiency, as I said earlier, is definitely going to be improved because of your drive strength. Power density, because you're able to integrate all the external buffers and sensing into your driver, the power density will be improved.
And then finally, reliability. Because of all the sensing the whole current sensing, the Miller clamp, and what have you. And in addition, you have the-- also what I did not mention here is just the inherent isolation ratings, all that adds value to this. So if you look at this, you-- this is kind of how do you kind of take care of improving your system challenge in a motor drive.
The same could be true for solar, that I'll show in the next slide. But fundamentally, if you look at the family of drivers, this is kind of-- if you go to the web, you'll see these drivers that's, right now, available. We'll have a lot more, but then just as an FYI, -Q1 means it's automotive, so you can use this for industrial and automotive, and this one will also be automotive. So we're trying to make this both industrial and automotive focused as well.
So here's an example of a solar string inverter, similar-- as you can see-- the similar inverter topology. The only difference here is that, typically, in solar, you're looking for much higher bus voltages, and that's because you're able to stack more and more solar panels in a typical farm like this, which is a, pretty much, a large farm.
And also, you need to have a high creepage and clearance, and this is something outside the scope of this discussion, but typically drivers also need to be aware of how it can withstand high clear-- how it can-- oh, how, why needs to have high clearance and create a creepage and clearance. And all that is because it could result in some external arcing or things like that.
And typically, in solar, that is of more importance because it's all exposed outside to the the environment, so there could be Altitude, humidity issues, and pollution and dust, et cetera. So that's why it is very important to do that.
And so to kind of sum up this family, we have a EVM, right now, so this is the link that you can go into, and it gives you the way and there is a user guide available. And you can actually go take this event EVM and kind of see how it can fit into your system and see if you can do a nice evaluation with this sport.
So now, let me jump ship and now talk about the next driver that just got released a few weeks back. This is the 21530, and this part is primarily used when you are looking at solutions where you need much higher efficiency and high power density. And so this is a four-amp, six-amp driver.
Again, it's targeted to drive IGBTs on silicon carbide, and this guy can go to very high frequencies for applications where you need very best-in-class, a very small prop delays, and pulse-width distortion. What does that mean? That means that you want to typically think about using this for converter applications like DC/DC or AC/DC converter applications where typical switching frequencies are on the order of 50 kilohertz, 100 kilohertz, or even beyond.
In the past, the faster applications that are talked about from the 217 part, they are typically in the-- right now, with IGBTs, which is like solar and motorized, that's what I highlighted, those applications are typically in the order of 10 kilohertz for IGBTs, and going beyond 20 kilohertz, like around 50 kilohertz, for silicon carbide. So that's fundamentally what you do.
For this one, it's you can go to much higher frequencies. Now, by the way, this doesn't mean that the driver is limited to that. It's primarily the application. So even the other part can go to higher switching frequencies. I'm just saying that this part is typically useful or kind of seemed to have more applications in these much higher switching frequencies, which is primarily these power supplies.
And here, so what is so unique about this part? So if you look at this part, this is a standard industry 16-pin footprint, and so I say wide body. The difference is that, notice that it says 14-pin. It's not 16 pins. As I said, it's a 16-pin footprint, but what we are doing here is we have taken the two pins out there-- 15 and 16, that's typically supposed to exist-- and you would see that if you were to type 21520 on the web. You would see that two pins up here.
So this is basically an offshoot of a predecessor part, which is 21520. So essentially, we fundamentally took these two pins out. And why am I doing this? Simply because you can improve your working voltage. So if you look at the system-level requirements, many customers would say, I need to have a big gap out there.
So if there is any external, I would say, pollution or anything potential arcing, you don't want it too close. So you want to have these metal pins far away, so that's fundamentally what it is. And these two pins, by the way, we were-- even though in the time, the other 16-pin part were basically no connect pins, simply for mechanical stability.
So we basically ended up changing the internal lead frame architecture. And then we came up with this, to make it the same to have it of the same mechanical stability. So that's fundamentally what this part is about.
Now, this is a 12 volt UVLO part, similar to the 217 part, and why 12 volt? Because 12 volt, in general, is very critical for silicon carbide and IGBT. So as I said, early on, you will learn something that you would-- it's basically so-- it's the minimum voltage only after which the power switch will start functioning. If you turn-- the power supply will turn off below that. Because if you're below that, so which is kind of what I'm trying to say out here, right.
So if you are below a particular VGS, which is your gate to source voltage, it can cause higher conduction loss. And that means it could-- your power switch could get heated up and eventually it could it'll definitely reduce your a switch lifetime on reliability.
Now, this 12-volt is also important, because many of these applications, especially for silicon carbide and IGBTs, they use dual supplies. So you see that there is a VSSA and VSSB. Each of them, this will be a dual supply. But then, it could also need to have a positive supply and negative supply. Positive supply, negative supply.
So the UVLO is typically, with respect to the ground voltage, and that's not necessarily zero. If it's a negative supply, you may end up having the 12 volt, which is starting from that. So if it is minus five, so your UVLO is actually minus five plus 12, which is seven volts. So that means it's very important to make sure that you're well about the-- and the voltage where you don't have enough losses. So that's why this is very important to highlight this.
So we have one nice reference design. I wanted to just spike this out because TI builds-- we try to solve problems from a system level, and we want to look at the customer problems. And we tried to illustrate what our parts can do to help you solve your problem. So this is called reference design.
And I'm just spiking out one for this part, and this is essentially a Dual Active Bridge reference design for an energy storage and or orient for industrial and also an onboard charger, typically for automotive. So this part has the 21530 that I talked about for this topology, along with TI's C2000 controller. That's additional controllers.
So this platform enables you to give-- to switch at high switching frequencies, and it also does soft switching. Soft switching means you-- basically, you try to cut down a lot of these switching losses and eventually you get a very high efficiency out there. It's a peak efficiency of 98%.
And just to kind of-- and lastly, I just want to talk about one slide on TI's isolation technology. So TI uses capacitive isolation, and typically, there are three isolation technologies in the market. Of those, magnetic and capacitor. Capacitor is something that offers the highest dielectric strength simply because we are using silicon dioxide.
It's a grown-- I mean, it's a known material dielectric, using the IC industry and, therefore, we are sensitive as an IC company. We are very well-versed in how to develop these silicon dioxide dielectrics in our devices, and you can see that the dielectric strength is certainly high. On the right, you can see an example of what kind of architecture we have, which is our double capacitive barrier, and that's how you get your reinforced isolation.
And so, in summary, we have a few things out there that I spiked out. Power density and isolation, that's the key for an isolated driver. And if you kind of boil it down to an isolated driver, what we are looking for is high working voltage, high drive strength, high immunity, and high power density.
And we saw this in all the-- both the drivers that I illustrated today, and those are the two drivers that I talked about, 217XX, 21530. Both these parts are available in the web. One has been released and it's expected the 217XX has been press released, and we'll be releasing sometime this year for market. But you can definitely get samples for that.
The 21530 is completely raised to market, and you can order huge quantities and you can actually use it fully as-- because it's a market release material. So you can go to TI.com get more on the applications and designs. And we talked about the capacitive isolation technology.
And finally, if you want to have more resources, it's all available out here in the video series. And we have a lot of white papers and blogs and tech notes, so all these things would be-- is there publicly available on the web. All right. So with that, let me now close from my side and I'm going to handle it or hand it over to Rob. Details
April 18, 2019
The new UCC217xx family isolated gate drivers with integrated sensing for IGBTs and SiC MOSFETs to save energy and protect high-voltage systems. The UCC21530 is an isolated dual-channel gate driver, with 4-A source and 6-A sink peak current, designed to drive IGBTs and SiC MOSFETs up to 5-MHz with best-in-class propagation delay and pulse-width distortion. arrow-top close delete download search sortingArrows zoom-in zoom-out arrow-down arrow-up arrowCircle-left arrowCircle-right blockDiagram calculator calendar chatBubble-double chatBubble-person chatBubble-single checkmark-circle chevron-down chevron-left chevron-right chevron-up chip clipboard close-circle crossReference dash document-generic document-pdfAcrobat document-web evaluationModule globe historyClock info-circle list lock mail myTI onlineDataSheet person phone question-circle referenceDesign shoppingCart star tools videos warning wiki