 Hi, I'm MPI, brought to you by DigiKey and Aged Fruit. Thank you, DigiKey. This week it's Nixperia. Lady Aida, what is the new product introduction? It's always known as I am MPI. Other week, this week. OK, so this week we're looking at Nixperia again. Some engineers may remember them when they were called NXP. They now have a new bitchin' logo with this cool X thing going on there. And we're going to look at the NBM 51 and 7100 series of chips. These are kind of interesting. So these are battery boost chips. They're little QFNs, as you see here. And the flyer, which I checked out, and I saw this actually posted on social media a couple other people noticed it. It's a very interesting chip. So this is designed to be used with lithium-coin batteries, not rechargeables, the premium metal lithium batteries, like CR2032. I think there's also like 2016. And then there's like the 2540s. They're very small. They're very energy-dense. But they have a couple downsides that makes them tough for use with IoT devices, particularly ones that have wireless transmission. Because you have that little burst of energy you need to transmit the data over Bluetooth, or ZB, or cellular, or even Wi-Fi, or ESP Now, or whatever. Laura, whatever your wireless transmission medium is. And people really like coin cell batteries because of their ultra-small size, energy density, and thinness. So even though we really love lithium-polymer batteries here, they're a little bit more expensive than coin cells. They do need to be recharged. And I have a recharging circuitry. Whereas coin batteries, they do have very good density. And you can get them at grocery stores. And users can replace them. So you've seen the Apple location tags, the ITags, and the tiles. They use coin batteries. They last many, many months because they're really smart about how they do their energy management. But then users can replace them very easily. And the batteries can be recycled. So you can pick up your standard CR2032 coin battery for $0.30 or less. These are 3.2 millimeters thick. And 20 millimeters wide. They give you 3 volts nominal. And they have about like 220, 240 milliamp hour batteries. These NBM51 and 71 chips also work with these lithium thionyl chloride. These are much more expensive, but they're incredibly power dense. And they give you 3.6 volts out. Notice that even though there's 3.6 volts, it's not a rechargeable lithium battery. These are still primary non-rechargeables. These are often used for real-time clocks or other industrial uses where you really need extremely high power density. And you don't mind spending, as you can see, they're about $5 a piece compared to the lithium coin cell batteries. But both of these can be used with the NBM series. OK. So here's showing a good example from the data sheet about why you'd want to use this. So on the left, you've got your standard coin cell battery, lithium manganese oxide. Again, about 240 milliamp hour, 3 volts nominal, the thionyl 3.6 volts. And you see the energy density compared to double A's, which are 200 watt hours per kilogram. The lithium coin cell, lithium metal coin cell batteries have about 50% more energy per gram. And the lithium thionyl has like two and a half times as much. So a really big difference. So why would you ever use alkaline batteries? Well, first of all, alkaline batteries are very expensive. And they're available also. But they're much larger. Even triple A's are the smallest batteries you can get are not anywhere near as small as your lithium coin cell. They're not as thin. And of course, you need the spring holder as well. But the most important thing that keeps people from being able to use coin batteries in a lot of cases when they have difficulty is that internal resistance that's documented at the bottom. For your alkaline batteries and your lithium polymer and ion batteries, and most reusable or rechargeable batteries, your internal resistance is really low. It's under an ohm. Whereas for these lithium metal batteries, the internal resistance resistance is quite high. At the beginning of life, 10 ohms. At the end of life, 70 ohms. So before you even get to, sorry, go to the left image. I swapped them. Before you even get the voltage out, your current is passing through what is called the IR, the internal resistance, which here is modeled as 9 ohms. Because in this datasheet for the energizer battery, they do show you how to calculate it. It's not purely linear. It depends a little bit on your drain and how often you're pulsing it. But basically, it's 10 ohms at least. So let's say you're drawing 100 milliamps out to a very small amount of time, only for 10 milliseconds. We're drawing 100 milliamps out to transmit data over Bluetooth. 100 milliamps isn't too much for your radio. That's going to give you a drop of 1 volt. Because 10 ohms, 100 milliamps, the math equals IR, your voltage drop is going to be 1 ohm. So what would normally be a 3-volt output across the battery is across the entire thing, 2 volts. And 2 volts is probably going to be too low for your micro controller or radio to run. And so you're going to get really bad performance. You're not going to get the distance you need, or you only needed that current for 10 milliseconds. Doesn't matter. The instantaneous voltage drop is still going to be there. So what can you do? Well, basically, don't try to draw a lot of current from a coin battery that's not what they're good for. Instead, what you can do is you can slowly sip current off. If you're sipping only 1 milliamp off instead of 100 milliamps, then instead of a 1 volt drop, you're going to get a 10 millivolt drop or something or less. And for a lot of IoT wireless little sensor nodes, they're not transmitting constantly. They're only going to be transmitting once every minute, five minutes, 10 minutes, maybe even once an hour. Like those little tile things, they don't transmit constantly. They're just kind of saying, hey, I'm here. And then they go back into an ultra deep sleep of a couple microampere or less of current during their deep sleep cycle. So what the NBM 7100 and 5100 does, as you can imagine, is it slowly sips current from the battery over a long period of time and then charges up this capacitor that it will store the current charge into. And then when your chip needs to drag that 100 milliamps out for that quick burst of wireless, it's like, boom, I'm going to provide that to you, but I'm providing it to you off of a non-high internal resistance component like a low ESR capacitor. So here's how it works. You've got the NBM chip here. And you see on the left, VBT, that's the battery. And you have a stabilizing capacitor there. You've got your inductor because inside is both a buck and a boost converter. It's actually boost than buck. The voltage gets boosted up, charges that cap on the top right of the schematic, a very big C store, boosts it up to 12 volts because you want to store a high amount of power. And the power is going to be the voltage and the capacitance. For small-scale capacitors, you're not going to be able to get really above 100 microfarads, but you can get higher voltages fairly easily without a lot of cost. So it's easier to boost up the voltage to 12 volts on the capacitor. And then when your microcontroller says it's ready, start, it needs current to transmit, it tells the chip the chip converts from the boost mode to the buck mode, and it books down from that charge stored on the capacitor down to your 3.3 volts or 2.8 volts or whatever you need. You transmit, the capacitor drains out, and then the cycle begins again. So you do have to specify that C store capacitor pretty well. And there is documentation. You can go through all the details. Basically, as a rough idea, if you're drawing 100 milliamps for 10 milliseconds, you need a 100 microfarad, 12 volts or 16-volt capacitor. There's conversion loss, 20% here and there. And of course, you want to over-specify because temperature and the DC offset can affect the capacitance. Basically, you end up with about 100 microfarads here. I think the calculator here is 100 microfarads. And then you also need a bypass cap on the input, 10 microfarads to stabilize it. And you can go through and actually do the math of how many joules of power do I need. So if you remember your introductory to electronics, physics classes from college, then basically doing that math like a problem set in here. But you follow the math and then figure out the capacitor and then you just lay it out. And they even show like, look, here's how big the circuit is compared to your CR2032. You still have enough space for your little wireless chip on the other side or even on the same side. The capacitor is going to be the largest component because it does have to buffer all of that power for the transmission. But it does it all for you. And then there's actually two versions of this chip. Well, there's four versions total. So you can program it over I-squirts your SPI. So you wonder, well, why do I need to I-squirts the SPI? You have to tell it for the buck and boost converter, what's the maximum voltage and how much current and how often you're going to probably use it. And you can set some specifications over I-squirts your SPI. There's also whether they support up to 5.5 volts or 11 volts output on the capacitor. You're going to figure out whether you need that extra voltage, that extra power storage for the A, for the seven series versus the five series. The I-squirts C version there is also, while you can configure it over I-squirts C, it also does free run. So if you're basically, you don't need to, you don't want to tweak and customize it. Or if your circuitry just doesn't have, you don't want to have to boot up and configure the I-squirts C, you want to just kind of run on its own. The I-squirts C version does have a free one. So you can choose between the NBM 71 or 5100A. And you don't have to set the registers or you can if you want. There is also an eval board that you can use. And you can break off the, it's kind of cute. You can snap off the board when you're done. But you can use it to experiment with different load settings, different timing settings. And there's also a PC software that lets you do the I-squirts C register configurations. If you so want to do so, again, there is a free running mode as well. So, you know, well, you're probably wondering, wow, I've got to spend a lot of money. No, it's about a dollar. It's a pretty good deal. And then of course your inductor and capacitor will be, you have 20 cents a piece each extra. It does at your cost, but it could easily triple your expected life because you're not going to be losing all that power, all that voltage to your internal resistance by slowly sipping the power and then bucking down when you need it and sending data over a Bluetooth or Wi-Fi or a Lora. So, a really good small solution for coin cell battery powered projects from the Dikean Xperia. And that's on API. Bye. On API.