 This week's IonMPI, brought to you by Digi-Key and Adivri, thank you Digi-Key, is from OnSami Lady. What is the IonMPI this week? Yes. This week's also, I want you to note, the new OnSami logo chain was a green circle. This is our new logo. It's quite nice. They've also now gone on a lower case. Do you like this one better? I kind of do. I dig it. I like how they're going all lower case. How can you argue with that? We had an idea for a game and it was going to be logos and names of electronic companies and you have to guess if it's real or not. I also think there's probably an opportunity to look at some of the, all the electronic companies are starting to redo their logos. I think everyone is like, we've got this budget now. It's budget time. We've got this thing. So OnSami new logo and what is the product that they're into? So this week we're doing the E-Fuse portfolio from OnSami. They actually have a couple different products. I think it's the NS54XX series, but we'll show you a screenshot of all the different options because there's quite a few. But E-Fuses are kind of neat. I've actually never used an E-Fuse like this before, so I actually learned a lot while researching this IonMPI and these are kind of cool. So normally when people think about fuses, you picture something like this, a glass or ceramic cylinder with two metal posts on the end inside of the wire. These are really great for detecting and stopping overcurrents. Like if you have a short circuit or something got damaged before too much current passes through your electronic device, possibly causing a fire or you're permanently damaging the device, you have this fuse which the wire inside is kind of calibrated so it will burn out after one amp or two amps or whatever current. The fuse burns out and you can see the wire broken. You know to replace it. A lot of people have your kitchen appliances, your microwave, stereos. They still often have, especially older ones, they'll have glass or ceramic fuses like this. We have multi-meters, half fuses that have had to replace. They're still used. They do a great job. They're extremely reliable. You can buy them anywhere. They're super cheap. And one thing that is kind of good, although it kind of drives users a little nuts, is when it blows it, it's permanent. It blows open and that's it. So you're like, the thing doesn't turn on. You have to remember to look at the fuse. If you don't want to have that, if you want to have something that it doesn't have to have a physical thing replaced each time and also these glass fuses are kind of large and bulky, a lot of electrical engineers use poly fuses. So these are a conductive, thin layer of material that as more current goes through it, it heats up, it heats up and eventually the resistance increases to a point where basically no current can flow through because it's like a huge amount of resistance. And then as the resistance drops, sorry, as the resistance increases, the current drops, the amount of power dissipated drops. And then it slowly, slowly, slowly comes back to room temperature and the resistance drops and it reopens. So it's the kind of opposite of those glass fuses in that when this trips, it opens the connection, basically disconnects the two pins, but it will self heal. It will sometime later, five minutes later work. Which is why a lot of people are like, oh, did your USB port stop working or something and your computer stopped working, turn off everything, unplug it, wait five minutes and turn it back on. That's what usually fixes it, is you're waiting for, you remove whatever the short is, you wait five minutes, it comes back down to temperature, the fuse resets and you're good to go. You'll see, we actually use basically this fuse in a lot of our stuff. Here's the Adafruit Metro, which has a mic controller born. You see there, handy red arrow pointing to the green poly fuse. And this is, basically if they're to protect your computer, your hub or your power supply when you plug it into USB and then you attach like five servo motors to the five volt pin and you're like trying to draw four amps through your USB port, your computer's unhappy. This just kind of protects your computer's USB port. The power will go out on the metro, five minutes later, of course, it'll come back to life and maybe you'll learn not to connect for servos. And this is the characteristic curve of this poly fuse. You'll see, depending on which product, the amount of current that you're passing through, how long it takes for it to trip. And you'll see it is dependent on, of course, ambient temperature and how much current. These are not super fast. They take 10 milliseconds to a second or two to trip. There's fast blow, slow blow, you can always get those details. But these are very analog. It's completely dependent on the thermal properties of that poly material in the center. Okay, so the E fuses like the NIS 5420 and again, there's a bunch of these. These are fully electronic fuses and they perform all the functions of the poly fuses or glass ceramic fuses, but they do a lot more. So the thing about glass fuses and those poly fuses is that they're really good for overcurrent protection. So if you're drawing too much current, they'll open up and save your device. But what they don't do is they don't protect against polarity. So if you have the wrong polarity, they don't protect about overvoltage. If you have too high a voltage or too low a voltage, they won't protect you. They don't do slew rate. So if your current bursts in too fast, they don't know how to slow it down. They're very, very simple. They're also really cheap. They're 10 cents. Spend a little bit more in electronic fuses. And these are, you know, they're analog electronics, but they do a lot more. So you can see inside they have overvoltage clamping. Of course, they do overcurrent protection. They do undervoltage lockouts. So if the voltage is too low, it won't kind of half connect, you know, brown out your device. There's also current monitoring. There's slew rate setting and, you know, a whole bunch of stuff. They basically do kind of everything. And what's nice is they sort of like work out of the box. They're very simple to use. So here's an example of the block diagram. VCC is power. Source is the, you know, what you want to connect your load to. There's a charge pump even for the P-channel FET so it can turn on, which is nice. It's high switching. iCurrentLimit, you can set with an external resistor. dV dt is the slew rate, so how fast you want the voltage to rise. You set that with an external capacitor. There's thermal shutdown, UV. You basically do all this stuff. It kind of does everything. So you don't need, you know, a lot of your protection circuitry is usually made of multiple diodes and maybe ziners and, you know, PFETs and fuses. This kind of does everything at once. So two things I thought weren't kind of cool. Of course, it does everything you'd expect a fuse to. But I liked the V-clamp. So, you know, it won't, it protects up to, I think, 18 volts, so it's not, you know, forever, forever. But if you have small spikes, like, you know, you have maybe an inductive load or something on your system that has some inductance to it, so you're getting spikes on the power supply that spike up, this will nicely smooth it out for you by clamping. Of course, if it clamps too much, it will overheat and the fuse, the e-fuse will blow. It won't be damaged. You'll just, like, open up the connection. But it'll take care of some, you know, basic overvoltaging. Slew rate control, another thing, you know, I don't usually use it, but I have seen some situations where people, like, I really want to slowly ramp up the voltage. I don't want to turn on too fast. I want things to sort of slowly come up, especially if you don't want, if you have, like, multiple power supplies and you want them to come up in order. So this will do slew rate control if you add a passive component to the device. They also come in multiple different sort of versions. So one thing is you'll notice there's 50-50 split between auto retry and sort of, like, you know, always off. So you can have a latching disabled. So basically, if it overheats or overcurrents, you have to remove power to reset it. And that's good when, you know, if something happened, you know, if there's some overvoltage, overcurrent failure or thermal failure, you don't want it to kind of cycle on and off. You want it to just turn off, and the user has to go and perform some action to power cycle it. Or there's auto retry, which is more like a poly fuse, right? You overheat, you wait, cool down, and restart. There's also different undervoltage lockouts, V-clamps, and whether or not you have a current sensing mirror output. So you can check the voltage. There's a voltage that is a, it's like a volt per amp, whatever, multiplier of the current. And so you can externally monitor with an ADC how much current is being drawn by your system. There's also multiple different voltages. There's three volt, five volt, 12 volt, and so I've got 24 volts. So, you know, they are hard-coded for the voltage, which I think makes sense. You know, these are designed for hard drives or computer cases. So, you know, you want it to be on the 12-volt line. You want any risk of a passive component will change what the voltage limit is or the undervoltage lockout or the style. So there's some things that are controllable, but some things that are basically kind of like set in the chip. So check out all the different varieties. A lot of them are in stocks. You'll just pick up whichever one you need. All right, available on Digikey. The one we're featuring today is the very latest one. It's the NIS5420, which is the 12-volt version in stock, and pretty cheap for about a buck. You can have a really nice... Almost 3,000 in stock. That's a lot. Which is more than most things. Yeah. Well, I want to make IMP. I want to make sure it's in stock. But so there you go. I think these are cool. So I might make a breakout for one of these chips, because they look very handy. All right, we have a little video about a minute or so. Do you want to play that? Yeah, let's play the video, and we'll... Hi, my name is Andrew Niles, and I'm an applications engineer at OnSemi-Conductor. Today, I'll be covering the comparison of an ETH use through a PTC, as well as a short demonstration of the ETH use features. An ETH use is an integrated circuit with many features, and a PTC is a special type of resistor, which has a positive temperature coefficient. Two important ETH use features are that they provide a fast current limit response time and on-off control with their enable pin. In this demo, I will show the ETH use responding to short circuits and providing PWM dimming for an LED circuit. The ETH use shown here today is the NIS5021, a new 12 volt, 12 amp ETH use. First, I'll demonstrate what happens when there is a short circuit. Setting the switch to ETH use mode, we will press the output short button. The short circuit being generated is a chattering short generated by a microcontroller. Due to the fast response of the ETH use, the 12 volt input voltage rail does not go down. It's also important to note the level of current. Right now, the current is 10 amps per division. For comparison, we will also do the short circuit with a PTC. When a short circuit occurs, they heat up and transition from a low-resistant state to a high-resistant state. Since the PTC must wait for heating, the response time is significantly slower than the ETH use. There is a larger amount of current, which causes the voltage on the power rail to go down. And that's this week's IonMPI. Thanks, everybody. IonMPI.