 Oh, great search brought to you by Digikey and Adafruit every single week lately uses a power of engineering help you, yes you find the things you need on digikey.com. What is the great search this week, Lady Aida? Okay, this week, great search is a buck boost converter that will run off of either two W batteries, or a five volt input and I, you know, we'd have a good ideal diode input into those. So assume that you have about two volts to five volts input and 3.3 volts output. Let's look at my schematic on the computer and I'll show what I'm replacing. Well, you hide this part, give me more, give me a little more space on the screen. So this is what I'm doing on this design, which is it's a little uncoture, but you know, bear with me. I have this board where VBAT is about two volts, it's two AA batteries, it's two to three volts and I want to get 3.3 volts out in the end, but I also have either AA batteries or five volts plugged in through USB. So this VBAT boosts up to 3.8 volts through this TPS 61023 and then it has a little like an OR diode power selector here with Vbus which is USB five volts and those go into an LDO to give me a clean 3.3 volt, which is fine. But it's a little bit like, you know, boosting and bucking, whatever. If you want to have like an all-in-one solution, what you could do is get a buck boost converter, something that will take either the high voltage Vbus 5.5 max, five volts, or as little as VBAT two volts and give you somewhere in between, right? So it's like, usually you have a boost converter from a low to high or buck converter from a high to low, but what if you have input that could be either higher or lower? You want a buck boost converter, right? Which is like great marketing. It's like, is it a bug? Is it a boost? Dessert topping, floor wax, buck boost converter. Let's go to digikey.com and we'll find a buck boost converter. So let's search for a buck boost. And we want a voltage regulator, not a controller. The controller is usually you have to connect external transistors and diodes. And you have to like, it's just, it controls the regulator, the regulation circuit. We want something that's all-in-one. We're a little lazy. We kind of want, you want like a bento box. It has a little bit of everything and we don't have to think too much. Let's go with something that's active and we want one output. The output we want is 3.3 volts. So we'll just say, hey, you know, it can be positive or negative or positive only. We don't want a negative output. Often, these DC converters can also invert the voltage for you, but we don't want that. We want something that's normally stocking. And just for now, we're going to exclude marketplace. So just stuff that's stocked at digikey right now. We also want a synchronous rectifier. That means that you don't need an external diode. It usually means your performance is a little bit better because instead of, you know, if you've ever studied buck or boost conversion, there's two switches, right? You're switching through an inductor back and forth. And sometimes people replace one of those switches with a diode. Very inexpensive, works very well. But if you want a little bit more efficiency and often the price isn't too different. And usually you get true power disconnection, a synchronous rectifier. I personally like synchronous rectifiers, but we all have our preferences. And then the input, the minimum input, remember, we're going to have two doubly batteries, doubly batteries, when they get down to like their lowest level, it's about, you know, 0.9 volts. So we want something that can handle 1.8 volt input at a minimum. And the maximum 5.5 or 6, that's fine because we're again USB is 5.5 max. So let's apply that really cut it down. Because we we limited we only want like a low voltage regulators. And there's a couple of really good options already. We're starting to see like a bunch of chips come in here and look at all these in stock components. Wow, isn't that wonderful? A real change to see so much in stock. One thing I don't want is anything with BGA, because I'm kind of not a fan of BGA. So I want to option click and I go through and I can you can search for filter, but you can't like reverse filter. So I'll, I'll go through and I'll de select those. Okay, so now I've got 100 options is a really good thing to look at. Okay, so you've got a couple options sorting by price looks like you're going to pay like about a dollar. Not too surprising ti is also she also let's look also in stock only. Alright, so we've got 56 options. Not surprisingly, rich tech they make a lot of power supplies regulators ti has a lot. And you'll notice that TPS 63 series. We actually stock a breakout board with the TPS 63. I think all their buck they have a line of buck boost converters called the TPS 63. 63 or 60 is what we use here. This is a five volt buck boost from three to 12 volts gives you like 500 milliamps or an amp. So it's here. These are nice chips. I've used this family before. So that's kind of good to know. There's a couple in this series. It looks like different current, you know, built in current limiting. There's also Rome. There's also a few that have different either adjustable or fixed outputs. So you see some of these are fixed sums of adjustable. Since 3.3 volts is really, really common, I'm going to just select 3.3 volt fixed output. Now you get down to like 10 options. Again, all these are going to be really good. I'm not going to say like the Renaissance one TI is good because I've used TI before. I'm probably going to just look at this one first. The next thing you want to look at is this. I mean, you want to simulate this and make sure it's of course, it's a good chip for you and TI has a good simulator for all their chips. But you have to kind of approximate how much current I'm going to need out of this thing. So I'm going to need about like at least 500mA to drive that speaker and the ESP32, especially if it's going into Wi-Fi mode. So like 500mA is kind of like my thing. But remember that the 500mA is not the switch current. The switch current has to be the max peak coming from inside the lowest voltage that could go in. So if you're at 1.8 volts, you're pretty much doubling. So I need at least 1 amp of switch current. And so these 800 and 900 are not, they're really at the limit. I don't think that they're going to necessarily be able to supply how much current I need. Because again, as the battery dies, I'll say it's going to be hard to get that much current out of a dead battery. But you know, you also have to give yourself some, give yourself like a 20-25% headroom for inefficiencies in the circuitry. So let's go with like a 1.6 plus current. It says output, but usually that's actually the switch current, not the current output, because on a buck boost, they're optimistic. And then some good options. So I actually kind of like this TPS 61 and 30. I mean, it's a dollar, which is a really good deal in quantity. And they have lots in stock. So this one is kind of nice. I mean, I've used this family, like look at the data sheet real fast. 1.8 to 5.5, up to 1.2 amp output and step down 800 milliamps from 2.4 volts. So yeah, about 500 milliamps from 1.8 volts. Really low quiescent current, which is good. I want it to work like I've mentioned in the previous segment. This is going to mostly be on all the time and only playing audio when somebody presses a button. So the boost converter will kind of always be running. So quiescent current, a good quiescent current is important. And also really simple, easy to schematic. I mean, some input bulk capacitance output. And then doctor notice, you don't need a diode because it's synchronous. And you don't need to do feedback. We're just a divider either because it's a fixed 3.3 volt output. So this is my pick the TPS 6301 and lovely buck boost converter. That's a great search.