 DigiKey and Adafruit present. Duh-duh. I am an MPI. Texas Instruments is our featured company on INMPI This Week by DigiKey and Adafruit. Lady Aida, what is this week's INMPI? OK. So this week's INMPI, as always, I go to digikey.com slash new. And I'm like, what is the new? Well, I used to do this all the time anyways. But now I'm sharing with you the thing that I found on that page that was the most interesting part of the week. And this week, it's this new Buckboost converter from TI. I love TI power regulators and Buckboost converters. They like, there's so many different ones. They cover like every range. They're super powerful. They're very integrated. And they always have these like touches that make you think like, wow, this person who designed this chip really thought about some cool and useful new functionality. I mean, power supplies are supposed to be like boring. But actually, they're kind of not. They're the most important part of your design, like the base of the design. The good power supply makes everything work out. And a bad power supply is going to cause you all sorts of headaches. So this week's MPI is the TPS, which I think is like Texas Instruments Power Systems. I don't know exactly what the TPS stands for. It's the TPS 63900. And this is a very tiny little chip that is a Buckboost converter that takes about 1.8 to 5 volts in and gives you a selectable 1.8 to 5 volts out. Here's a simplified schematic. So one thing you'll notice is, of course, it's a synchronous. It's the transistors are all internal. So you don't need an external transistor. You don't need an external diode, a shocky diode. It's really easy to use. You've got an input capacitor, output capacitor, and then the inductor. One thing that's neat is that this is a Buckboost converter, only one inductor needed. And it's about the same price as a Buckboost converter, but to get both peanut butter and jelly together in one. When you have a voltage, let's say you want to have a voltage of about 3.3 volts. That's a pretty common voltage for most electronics. But you're using something like a couple alkaline batteries or using a lithium polymer or lithium ion cell. Well, a lithium ion cell or lipoly is going to be 4.2 volts when fully charged. It's higher than your output desire of 3.3. But then as the battery gets run down, it drops down to as low as 2.7 or even 2.5 volts. And that's below 3.3 volts. You want to boost that voltage up. So what's nice here is no matter what the V in is, between 1.8 or 5.5 volts, the output is going to be a steady voltage. And it will automatically switch between the two modes of operation in order to maintain that clean 3.3 volt output, which is wonderful. This means you're getting the most power out of the battery, really just draining it, but also getting the exact voltage you need. And something that's interesting that you can see here is there's those three configuration resistors. We'll chat about those in a moment, because this Buckleys converter has an interesting dual output selection mode. OK, so one thing that I thought was neat is if you go to TI's YouTube page, they have a whole webinar that is 45 minutes long, and it talks about all of your different buck boosts. They talk about this one, but it also has this nice diagram that shows you their family of boost and buck boost converters. And there's a lot of chips that TI makes for this power regulation and boosting. So I thought this was handy to kind of bookmark this. I want to go watch this in more detail after the show, because depending on your current outputs and your quiescent current, you might want to have a different selection. So this chip, you see, it's right there in the middle. It's that sweet spot. It's got an internal switch of about 1.5 amps. Note that doesn't mean that the output is 1.5 amps. It means the switch that is inside that does the boosting or bucking or multiple switches is about 1.5. The actual current you're going to get is, I think, for boosting, it's about half an amp at 400 milliamps. And then in buck mode, I think it's about 600 milliamps. So it's over 300 milliamps or so, depending, of course, on the voltage input output. But what's really nice is the ultra-low quiescent current under a microamp. That's not on a typo. It's not under a milliamp. It's under a microamp for the quiescent current, which means that this is an excellent chip for use with wireless devices that you only need to send data once in a while. So this is what they're kind of picking. They're sort of saying, this is really good for your Lora WAN. This is really good for your BLE. This is even good for maybe something that is Wi-Fi. Something that only wakes up once in a while. But you do need to have a really good solid power supply at that time, and that spends most of its time asleep. So they're like, why ultra-low IQ DC DC needed? And usually DC DC are not low quiescent. Usually that's one of the things that you give up when you move from an LDO to a DC DC. But especially when you have these devices that, again, they wake up once a day, once an hour, they take a measurement, they transmit it, and they go back to sleep, the quiescent current becomes the dominant power usage. Even though it's extremely low, the amount of time that you're spending in that low power mode is so long that it actually starts becoming, that the quiescent current starts to really matter, even though it's so low compared to the running current. Maybe it's like three orders of magnitude less, but it's three orders of magnitude as long. So that's why for wireless, they call this pulse-load applications, the quiescent is important. So I thought that this was a really nice little chip that can handle, kind of does a little bit of everything. It's like a bento box of converters. It's got some nice specifications. You can see there, it can give you up to over 600 milliamp output if you need. So you can use it for some low power, not multi-amp, maybe not like cellular wireless transmissions, but definitely will do your Bluetooth, your BLE, your Lora, your ZigBee, your Z-Wave, all those things, which, again, low quiescent, long time asleep, wake up once in a while, do something. This is the other thing that they had, which I thought was, at first I was like, why is this at all interesting? Then I thought about how you would implement it if it wasn't built into the converter. And I was like, oh, yeah, that would totally suck. So it's really nice it's built in. So when you're doing your measurement, let's say you have a little Bluetooth wireless temperature humidity sensor. And you want to take a measurement every five minutes and transmit it to HomeKit, your hub that is measuring data from around your house. This is a home automation project. So for that, you're going to be asleep for five minutes. So that's where the low quiescent current is so important. And then you're going to wake up. And before you turn your radio on, before you turn on the Bluetooth or Wi-Fi or whatever, you're going to want to get some things going. You might want to configure your memory. You might want to read some EEPOM. You might want to take some sensor readings. And all that can, maybe it's not going to take that long, but it does matter. And for those sensors and those devices, you might be able to run at 1.8 volts. And if you're in an LDO mode, only it won't be that important. Maybe it doesn't matter. But if you're using a buck boost, you can actually save a little bit of current. By starting up and running your MCU at 1.8 volts to take advantage of that lower voltage and not turn on your radio, which is going to be that high current, higher voltage, that's going to need 3.3 volts or 4 volts or whatever. And then right when you're about ready to transmit, boom, you tell the DC-DC converter, hey, instead of giving me 2 volts, give me 3.3 volts, everything powers up much higher all at once. You do your transmission, and then you can go back to sleep at, again, the lower voltage. So to do that, if you go back to the first image, sorry, the second image, the first if you count by 0, on the right you see the config resistors. So those resistors, normally, if you've made a couple buck boost converters, you're like, hey, where's my resistor divider? Usually you have a resistor divider on the output that sets the output voltage. That's how it's going on here. Instead, it uses these single resistors to set the voltage, and you're probably like, well, how do you tune the voltage? Well, there's a table, and the resistor value correlates with an output that goes up by 100 millivolts at a time. But check out the datasheet. There's a whole table there. So you have three resistors. The first two, I think, are the two voltage output options. And the third one is the input current limit, which I won't cover here. Again, the datasheet in the webinar does. And then if you see on the left, there's the cell select line. Well, when that pit is high or low, it determines which output voltage you're selecting. And if you think about, well, how would you do this normally? It's like, well, you could do it by messing with the voltage divider on your DC-DC converter. But some of you have all these transistors on their low side, and you have to switch them. And you have to switch them instantly so you don't get both off at the same time. So you actually understand why they're like, have this all integrated and have a little selector, and it does the logic for you. So I think this is kind of neat. It's an interesting thing of, OK, you really need to, you know, you have a small battery. Maybe it's a coin cell, or maybe it's like a 50 milliamp hour battery. How do you run your hardware as long as possible? And I think this is a, it's a not expensive chip. It's like $1 or so, and it does the job quite well. So this is on DigiKey, and you can find it by using the short URL, digikey.com, or you can look at this part number that's on the screen, or you can follow the links that we have in the blog post, or in the channel, or more. It's easy to find. Lydia just shows you how, and that is this week's. OK, I will show you really quickly. If we go to the overhead, I'll show the valve board, which I picked up. TI makes a nice, simple valve boards. So you're like, what's going on here? So this is actually all of the converter, right? This little section here, you've got this inductor. It's actually like a chip style inductor. Input output capacitor, a lovely little layout. They have some options for bigger capacitors if you want. And then these are all of those resistors. Remember I said the resistor sets the output voltage in the current limit? Well, you would use these to set this value here. You can see the switch here for the different values you can set, and that correlates with an output voltage and a current limit. So I think it's actually one of the few times where I'm like, if you really have to mess with all the resistors, it's kind of nice that these all come with dip switches ready to go. But the full solution is so small. And then, of course, these can be a 402 resistors. So really, it's only a few millimeters square. Just about everyone in the chat was saying, I was looking for a boost converter. Love DC boost converters. This is awesome. Thank you for the ideas. This is one of, I think, the best MPIs that you've done this year. It's useful. OK, I'm going to use it. This week's RMPI. Hi, I'm MPI.