ON Semiconductor Corporation (ON) Earnings Call Transcript & Summary

Good morning, everyone, and welcome to today's webinar on the review of circuit protection systems contract [Audio Gap]. Both with intelligent power I'm [ Christy ]. In today's session, we will review the circuit protection systems showing how our semi intelligent power solutions are used to provide the different types of requirements for ground fault circuit protection and contactors. At the end of the webinar, we'll be holding a Q&A session to answer any questions you may have. You can tag your questions into the Ask Question box on your right. A recording of this webinar will be shared with you via e-mail. Now let's meet today's presenter. Jonathan Harper is member of the Technical Staff at [indiscernible] , discovering energy infrastructure and European marketing for the Advanced Solutions Group. Now let's go ahead and get started. John, the floor is yours.

Good morning, everybody. Let's look -- so the presentation today is about solutions for circuit protection using intelligent sensing and intelligent power. So we'd start talking about what is circuit protection, talk about distribution box, what's in distribution box. And we'll look at the differences between Europe and the U.S. when it comes to circuit protection. Then we have a look at 3 types of protection, which is overload protection, ground fault, interrupt protection and artful protection. Then we go into our solutions for ground force protection, then we can look at how we can use SiC MOSFETs to improve the reliability of systems. And then how we can drive the contactors and other circuit protection devices and related equipment like soft starters with products with better connectivity, for example, connectivity with 10-based T1s, networking system and with BLE. So let's get started. Circuit protection. So I'm showing a distribution box installed in Germany in 1999. So -- just to give you an idea of what's in a distribution box and what sort of protection. First of all, you see here fuses and the German apartments 3 phases come into the flat, only one's actually used for the meter normally, in our case, one fuse is used. Then you have a number of miniature circuit breakers, which are mechanical, electromechanical circuit breakers. And then you have a residual current circuit breaker in this setup. So you can see here the -- so this is connected just in this case to the bathroom. So the bathroom has 2 circuits, which I've switched off in this case. One is the circuit protection, which is the fuse to the bathroom, if you like, and this is the residual circuit breaker for the bathroom as well, which is also switched off. If you look at this, the markets in Europe and the U.S., you see very different uses of circuit breakers. So here is the bathroom. It has a normal German plug. So I have a German socket. And this has a normal plug. There's no special protection on it. The protection comes from the circuit breaker on the wall. If you look at a U.S. apartment or building, you will see that there's a circuit breaker on -- sorry, a RCD system on the power outlet and there's also an appliance RCD on the hairdryer in this case. So there are 3 different types of protection you have in the Europe, in Europe and the U.S. So -- this is -- explains why there's a very large market for circuit breakers in the U.S. and less so in Europe. So let's have a look at the circuit protection elements. The circuit protection elements, very simply is a fuse. It's a way of protecting against over current. So remember in the old days, you didn't have the circuit breakers, so you can see which one was tripped like you could in the picture before. You'd have to go and look at all the fuses and check which one it was, and check the wire if it's broken off and then replace the wire. So the new circuit breakers are a little bit more convenient. So these miniature circuit breakers have 3 functions. It protects the circuit and how does it do that? It monitors the current and switches it off if it's too high. These are the miniature circuit breakers. Then you have a class of products called RCD. RCD is split up into 2 functions. One is RCCB, which is residual current detection and protection. -- which is RCCB. And in the U.S., that's called ground for circuit interrupter. And that protects if the circuit flowing in and out of [indiscernible] can explain that a little bit later. Then we have the appliance leakage circuit interrupter which is what you saw in the hair dryer in the previous picture. And then there's a portable GFCI adapter. So if you're going to use an electric, let's say, lawn mower and you have one you use outside you should really have a ground for protection on that device. So you should use an external adapter connected to the outlet. And that is a portable residual current detect device. Then there's a final one is arc fault circuit interrupt. This is the third type of fault you get at, and we'll talk a little bit about that later. It's pretty important. So the combinations, if you have a circuit breaker plus a residual current breaker that's called our RCBO. You saw in the picture before you had a circuit -- just go back to that. You had the circuit breaker has to be tripped and active and the circuit protection device, the overload protection are independent of each other. This would only tell you if there's a residual current, but it won't detect one trip if there's an overload. This will only trip if there's an overload it won't trip if there's a residual current. So you have to combine both of those together in series to get that protection. If you do that, that's called the RCBO device, then there's CBR, that's a name which is a third class of residual current detectors. This is a CBR [ master serve ] . That's something which, once it triggers, you can't just reset it like you could in an apartment or house. You'd have to get some special electrician to come in and check why it's triggered before it gets recent. These devices have relays. And these relays can also be used in other applications. For example, a motor starter is a relay with normally with a sort of [ Arista ] type of approach to soft start the motor and more modern systems use back-to-back SiC MOSFETs in parallel with the switching -- the relays. And so that's a sort of related type of application. And because once you have that functionality in there, you've got -- you can then immediately put in protection for those circuits. So circuit protection comes in with the timers, it comes in the motor starters, it comes in to contactors. So it's not maybe the primary function to do protection, but it also -- there's no -- it's quite easy to include protection in those devices once you have those solid state switches. And finally, an AC/EV charging station is just like if you like a big plug, a socket. We show that in the next slide, right? So over current, overload protection and monitoring, let's go through the different types of protection. So you have the magnetic circuit breakers, what it is, it has 2 things in it. It has a biometalic strip, which bends open if you get things gets too hot, breaks contact in terms of heat sensitive device. Then there's an additional solenoid in there which pulls the contacts if there's too much current flow through those contacts. Then you have relays and contactors. This can be used for overload protection with extra sensing. So you can -- for protection mechanism, you need to add a detection on that. But what you have is a simple relay. And those relays have 2 problems. First of all, when you have a capacity load, you have a high surge current, and that kind of starts melting the contacts on the relay and sooner or later, the relay will fail because of that. And the other thing is that if you have an inductive load, you need to have a capacitor in there which we'll talk in a moment. So that extra current going -- when you charge that capacitor up will actually is the same effect of capacity load also weaken the circuit and cause long-term reliability problems. So for the contactor to work correctly, as a protection device, you want to -- it's good to have a means of improving the reliability of that relay contactor. Then of course, you have to switch loads with an inductive content as well. And with the loads of an inductive content, you want to have a [ snubber circuit ] which protects against the DVDT. Remember we're switching AC circuits here. So you can't just go and put a diode across -- diode between here and here -- in fact, you can't even put a [ barista ] between here and here because, for example, this could be an induction motor, we don't even have access at this point. So this is why you have to protect a switch rather than the load in this case. So you have a snubber circuit to stop too high DVDT. And the other effect -- the other benefit of this capacitor is when it's turned on when its relay is switched on, obviously, this capacity is at 0 volts. And this will help prevent arcing problem. So that's arcing problems is another topic which you get when you have contactors. So in conclusion, when you have -- when the contactor opens, you have arcing problems and you suppress at the capacitor. But when you charge that capacitor up, when you shove it, you get extra current going through the contacts and then there's reliability problems. And semiconductor switches in parallel with those contacts can improve the reliability. Arc fault protection. -- Arc fault protection is an important upcoming topic. What that does is it detects arcing in circuits connected to a distribution box. So how do you get arcing? So you got 2 connections, right, like this, right, let's say, and then you've got a lose connection. So there's a gap between that and then you get a spark going between. So in this simple example, which I'm showing my fingers, you have the -- you've got the 2 circuit protections, which I've shown before. The overload protection won't trigger because there's no overload, it's just a bit of sparking. The ground fault detection, in this case, won't trigger because there's no leakage circuit to ground. So there's no detection, no trigger. However, this sparking will cause gradual destruction of the insulation, cause overheating, there's risk, of course of fire. So arc fault AFCI devices are very important and often used in buildings like hospital so if people it's a lot of people in, where the effect of a fire would be really catastrophic. But I think more and more buildings will be using arc fault interrupters. So it's difficult to detect. A ground fault circuit will detect in a special case where the insulation breaks and you get a fault to ground, but you can't rely on that. maybe the arc is not strong enough, doesn't have the -- doesn't trigger the device, the ground fault detection. So how does this work? You have a microcontroller, a DSP or custom circuit monitors the current and voltage waveforms to detect these arcing patterns. Finally, ground fault current. It's ground fault current. So what happens is, let's say, this load take 10 amps, right? You have 10 amps going this way, plus an extra 10 milliamps, yes, 10-amps plus 10 milliamps going this way. 10 milliamps going to the guy touch in the contact and only 10 amps going back, there's a difference of 10 milli-amps in that contract. You get 10 milliamps going through someone, that starts to become a problem. So you really want to -- so you say, hey, the current going this way and the current going that way is different. We detect it. we trip the circuits. Unless it's the ground fault current detection. Notice here, we have the neutral wires connected to the breaker. So there's different types of standard. I'm taking the U.S. standards, which is Class A and Class B, and you can either stop if it's over 6 milliamps AC or 20 milliamps AC. But for safety, you want to be below 10 milliamps AC, so 6 milliamps AC is good our limit. For the appliance, we showed for that hair dryer earlier, 6 milliamps AC is what's required to trigger it. We have -- one of the problems is what happens when you have the ground in neutral. So here, we've got the neutral is locally grounded, right? So what happens is the current get shared between the resistance of the person and the resistance of the ground in neutral. So the ground in neutral is a wiring force and normally won't cause any problems. On an electric circuit, it's hard to detect if that's grounded. But that's actually required to detect this because the circuit should trigger even if there's a ground in neutral. So you have to detect that ground in neutral and register that as a force as well. It's not needed on the appliance, we'll get a grounding neutral appliance. That's extremely unlikely to happen there. So it's not part of that standard, but this is where you have to have this protection. So finally, before we talk about the details of ground fault interruption, we can we talk about the -- this plug. So normally, this case is covered. This is an [indiscernible] charging station and somebody's very kindly put their finger out to lift up this flap. So you see this flap is where there is an outlet. This is a power outlet just like anything else. It also needs ground fault protection, overload protection, overvoltage protection as well. There's different standards in Europe and the U.S. So the U.S. has a standard a 5 milliamps or 20 milliamps protection using a similar process to what we discussed earlier. And then finally, we have the -- in Europe, it's a little bit more complicated. You have to have a 6 milliamps DC leakage and 30 milliamps DC leakage. So that's another market which is growing because the EV charges have these outlets, you've got to protect them. if somebody -- if this is switched, obviously, there's extra protection because somebody's got this switched on, and they only switch on if a person paid for it. And if there's a car there with the right protocol, but even so you can have failures in the insulation in the car which can cause ground leakage and you've really got to protect against them. So it's extra special protection in Europe for the DC leakage, which [indiscernible] Then we see here, it's RCD, GFCI, LCI devices, they're supposed to be tested every month. So it says here, this is in Germany, it says here press monthly -- and this is -- you're supposed to test these every 30 days. I guess most people don't actually do that. So because of that, the U.S. introduced self-test rules for portable GFCI and other appliances. And these are the different types of failure mode for testing. So it's quite rigorous testings. If we think of the German connector circuit break we have just tested this, okay. Whereas here, there's quite a lot of detailed testing needed sort of to make sure there's no problems on the devices. So I want to now go through the next bit, which is to talk about self-test RCD and GFCI solutions. So we offer a full range of solutions for the different applications. So the first application is to a GFCI using a single coil and that's used for power outlets. And then if you want to have a lower power consumption, you can do that grounding neutral detection with a extra coil. So we have a solution for that. Then there's the portable GFCI solution, which is this with solenoid drive. And then we have a self-test ALCI solutions, the thing which is sort of a hairdryer example earlier. So what you have is you have the circuit, which is -- I pressed on the -- you've got a back button there, sorry about that. So this is the current transformer. So the current transformer, basically measures the difference in the current between those 2 wires. You need a special DSP for detecting the ground and neutral fault. So we have a patented impedance measurement and signal processing technology to detect that difficult fault to see the way for the moment how you can do that. So what happens, it starts up 66 milliseconds after reset and del test repeats. And then if it fails, it goes in every second. And then if it fails 3 consecutive times, there'll be a failure and that's it so there's an immediate -- and there's a test to make sure that the SCR, which triggers the device will actually work. So we have a single coil and engine for monitoring as a dual coil engine on the new -- other devices. We have -- the main point here is how do you determine the difference between a valid fault and a failure. So you have, it's called usage tripping when you trip by mistake. But there's an adaptive filtering algorithm to detect this. And there's a very low bond [ cut ] for these types. And as Chris will tell you later, you can download this presentation and the details. Of these features, I just show you the circuit component count for receptacles. This is the power outlet is very low. You've got one current transformer, you've got the devices -- to the tripping devices and you have the power supply for the device here we redirected power up the circuit. And it's a relatively simple circuit with few extra components. And then for the RCPO, there's an extra solenoid, which you can drive to turn off the device as well. As you see here, this is the circuitry is showing how we do the self test. This is the ground fault test being active. And then this is the special stimulus you can use for ground neutral tests using our advanced intelligence tensing technology. And then we do an SCR test and they check that the SCR works and so that it really will trigger to make sure that the system is very highly reliable. By adding a second coil, one for the ground in neutral, you will get a -- you get a lower power consumption. So the stand by power of this device is only 575 [ micrograms ], and it was in the milli amp range of the other devices. So this is a lower power version of the device. We add a solenoid to this. Solanoid drive, we can do the portable and this is things used for lawnmowers and you can add the extra solanoid to trip the switch. So this has got a breaker as well in there. It's an RCBO functionality. And then finally, we have the appliance for the ALCI. So the -- this is specially made for the appliance. It's got to fit in the plug of a hair dryer, so it better be small, and this is a very compact solution. See's got a very few small components in there and you've got smaller devices. And this is the -- this is the product for appliance manufacturers. So in total, we have products to support ground fault self-test for -- adapt for power outlets, one with a little power, one of the portable power adaptor with circuit breaker and one for these suppliers. So that's the what we're looking here. We can see here is an example of how we do the self-test and for the appliances self test is -- the status warning's a flashing LED, the way the specification is written is can trigger the circuit, but it's important to have a flashing LED to indicate to the user that has a problem with their device and their appliance. So this is then the summary of the products we to look at later to see what it's doing. I'll also tell you which standards this works with and which standards is -- which EV charging standards full support. Now let's have a look at improving the reliability of the circuit using SiC MOSFETs. So we talked about the relay with the numbers circuit before. So what you can do is you can put in a bidirectional switch in parallel with the relay. By putting a bidirectional switch in parallel with that relay you can make sure that the voltage across the relay is 0 without having to use the snubber capacitor. So you would -- what this does is it basically takes the current away. This can cope, of course, with the current. Current of the snubber capacity we'll go through here. While a current for a capacitor load, we'll go through here. So you turn this on first and then you turn on the relay. And then you -- when you turn off, you turn off the relay when it's active and then you take off the switch, that will also prevent arcing. So I've looked at the web and these are called hybrid, for example, hybrid motors soft starters, we also protection. You can have 10x higher switch cycles when you're using parallel semi-conduct switches. You also -- when you turn these switches on and off in a circuit breaker mode, -- so not in circuit breaker mode you'll have high DVDT. So it's very good to have high DVDT isolated drivers to drive this. So if you are switching, of course, the motor soft start, you're going to be switching on with the nominal current and you're not too worried about that. So you switch on at the 0 crossing and off at some point of the phase current to do that. So you don't need to worry about that. But you also -- you will also use this for protection, switch off with protection in its gates because it'd be stupid not to have protection there. And the circuit -- this -- you'd have a very, very high current. When you have a high current going through semiconductor switch, the high current will cause a very rapid drop in voltage it as the current forces the discharge of the capacitor. So we recommend high DVDT switches with high DVDT immunity for these applications. I've chosen here a dual switch, the bidirectional switch. I think it depends on the application, how you want to drive it. Some people use -- won't have separate control of the switch some people want different long control a long switch. But I think it's -- maybe could have 2 independently controlled switches. In this case, they will not be individually isolated. So the isolation here and here will not be there, but that would be probably -- so got good CMTI characteristics, which makes it very suitable for this application. Let's look at how we can use Bluetooth and 10-based T1s to get more information about these switches. So let's go back to my distribution box. So if I look at my distribution box here, I can see that this switch is turned off and this switch is turned on. So I can see that's okay. But it's like -- how do I see if one of these fuses is blown -- these are 3 fast fuses? How do I have my tech? I can't have to go and look at it to see and check -- there's no -- so that's not a problem for apartment, but for a large building, when you have switches like this, it's good to have the communication to see whether the main switch is tripped or not and maybe depending on the [Audio Gap] So I'd say there's 2 ways you can do this. One is to have Bluetooth low energy connectivity, for the individual switches. Maybe in this example this, I think, would be an overkill maybe one switch to the main switch. There's actually no main switch here to some of the fuses, but in modern devices, you have one main switch covering that. And then the Bluetooth covering the main switch to see if it's on or off. and then individual diagnostics, depending on the importance and value of the load, right? If the lights in my living room are off right, it's not a real high risk or high cost problem to solve. But if you have this factory, and this is an important piece of equipment, which has been triggered off, you want to know quickly which one it is and detect that. So it depends on the cost of the downtime, whether it makes sense to have the connectivity there or not the Bluetooth. The other thing is to use single pair Ethernet. So single-pay Ethernet, for example, the range here 10-based T1s, short-range similar for ethernet is ideal for this application. We've got a very compact, very small solutions as you'll see in a moment for these products. So connecting that and then having some kind of Bluetooth connectivity to the main sort of node here is pretty normal. So this is when 10-based T1s was defined, this was one of the original applications presented at the IEEE was contactors and breakers -- by the committee setting this up. So how do we do monitoring with our Bluetooth chip. So we have 2 Bluetooth chips, [indiscernible] -- so what you can do is you can take a 10 milliamp LDO. We have LDOs, which goes straight to their mains and replace these capacity dividers, which are quite bulky, very compact very effective solution, and you can power up the device. So here, we'd use that for monitoring. 10 milliamps is not going to be enough to probably drive relays but it's enough [indiscernible] extremely low power device and can provide connectivity. So this could monitor the status of the contactor, it could do -- it'd just be a monitoring type approach. If you want a bit more power, so you can use this to drive things you could use a AC switching regulator, a typical buck converter. This is in [ S7 ] package size of [indiscernible] so we see pin for creepage reasons. So you can have 3 devices here to power that device off. So this will be monitoring it's not, let's say, driving -- so that's -- this is the small product we have for -- this is SLIC 7, as we talked about, -- and depending on what input voltage you're using, you can get something like 3.3 -- you can have 3.3 watts. If you've got a better cooling, you can go up to higher levels, stuff which works on European only, you can get a bit more power out of that. We can use a lower cost device if you want to do that. So single [ bulk ] will drive that. And then you connect to the wireless controller. So we have a number of products, one was controller. We have the released t15QFN device, triggered the the QFM device. We have the wafer level CSP that's we're going to be a bit smaller for our switch applications but also a possibility. And then there's the system in package and which has got the antennas in there, less the automotive part with QFM devices, which will be released pretty soon. Then we have the -- this is what's in there. It's a [indiscernible] 15 has a M33 core. It has all the trust side of crypto cell stuff, which you needed for cybersecurity. This is quite important. Somebody can't hack your system, even if they're monitoring. Even it's just use of monitoring, you don't want to have somebody coming and hacking your system and trying to turn it off. This is why we recommend the M33 coil with this trust zone -- it's pretty important to do that. And this is more than enough capability for doing a simple control for a contactor on top of the RSL on top of the Bluetooth connectivity, which is [indiscernible]. And this comes with a Bluetooth stack already there. Then we have the more advanced circuit. I put in -- here we're driving the SIC MOSFET. So driving the SIC MOSFET, you need the driver [indiscernible] application, you want to isolate it -- you will have -- certainly be isolated. I guess you need optical isolation is better to get higher DVDT -- sorry, the optical galvanic violation, excuse me, is give you a higher DVDT rating -- if you use a junction -- you can also use a junction isolated device by depending on a specific application. Well, I've shown the Galvanic isolated driver here. And then you can have the primary site flyback controller. You need the fly back controller because you've got to [ parity ] the power supply. You also got the gate drivers. That's more an extra thing you need with the isolated gate driver. And then you can connect together with a 10-based T1s with a simple connection to our connection and with Bluetooth. So all the bits -- the only contacts you need are the, obviously, main power contacts which is the load out and the input and the line, they're neutral or in your application 3-phase inputs. Then on top of that, you can get away with a solution which just uses 2 extra contacts. That's pretty powerful. So that's, I think, in a benefit in itself. So you've got Bluetooth connectivity and 10-based T1s connectivity here. So what -- so this 10-based T1s [ MAC [is] a very small device. You see this is a European $0.02 coin, and this is the size of the MAC and you need -- you've got a common mode choke terminations on each device. And then that's all you need to do a full solution. For the 10-based T1s and then you connect it to an RSL 15. So this is RSL 10 board. We also have the RSL 15, -- we did it with RSL 10 it was available at the time we programmed it. So we have combining the RSL 10 and the NTA26010 you get a very, very compact solution. Obviously, there's 2 evaluation also make it look much bigger, but the RSL 10 is fit or 15 would be here the RSL list device is here. So it's a very small compact solution, gives you full connectivity to that. You've got the code if you click on this link, I think that's to be working on the PDF files. So you click on this link, or look on our website, you can see the code is there already ready to download for this simple kind of connectivity solution. So with that, I've come to the end of the presentation. I'd like to hand back to Chris.

Thanks a lot Jon, for this excellent presentation. [Operator Instructions] And then let's see if we got any questions. So no questions for Jon yet. So if you would still like to submit a question, please do so now. Let's give it a minute. Okay. So I see no questions coming in. So then I would like to thank Jon again, and of course, all of you for attending, and then we hope to see again soon. Have a nice day -- thank you.

Thank you all. Have a great day. Thank you.