 Where is DigiKey? It's a great search brought to you by DigiKey and Adafruit. This is when we use Ladiator's powers of engineering and smarts and decades of using the internet and digikey.com to help you find what you're looking for. Ladiator, what's on the great search this week? This week I'm looking for a smaller package for a power p-channel MOSFET that I use for the power supply on my featherboards because I wanted to shrink my featherboard down to make it a little smaller. And interestingly I use a SOP23 p-channel FET, but let's look at what I used instead. So at the computer. So this is the original feather design that I'm going to shrink down a little bit. This is a standard SOP23 channel p-fet. I use the DMG3415 or 2305 pre-standard. The important things for me are you can pass a lot of current. So at least two amps. Even in this particular case it doesn't pass that much current and passes maybe like, you know, a one amp peak. But oftentimes I use this same part in a couple different spots in design. So I want to make sure that it still maintains at high spec. It also should have a very low RDS on. Some p-channel FETs have like, you know, two, three ohms. I want this to be 50 micro, sorry, 50 milli ohms or less. I also want a pretty low VGS threshold. So what's the voltage required turned on? Should be about a volt or less because I'm dealing with three volt logic. And often the VGS is like, you know, specced at like less than a milliamp of current. So, you know, I want to make sure that I'm well above that. And again, I want smaller than the SOP23 I've got here. So, and, you know, the other thing like VDS, you know, in this case it's 20 volts. So basically it's like a smaller version of this. SOP23 is kind of the standard size for small power transistors. You know, you're, you tend to go that or maybe SOP223. And then you get into like the power DI package sizes. But, you know, SOP23 is very standard. So I want something smaller, but not BGA, because again BGA is, you know, not great for my workflow. I want something that's like a, you know, DFN or QFN or whatever. But smaller in some respects to this. So this is the part that I tend, you know, I've used historically. You can see why there's a lot in stock. You know, it's a very popular part for many people. 20 volt, 4 amps, SOP23. Again, you know, about 50 milli ohms RDS on. And let me get a little bigger. Hold on, sorry. 50 milli ohm RDS on, 20 volt drain to source, 4 amps continuous. It doesn't need to be 4 amp continuous, but you know, I tend to use this for a couple different things. VGS on is about a volt or less. I don't care as much about gate charger input capacitance, because I'm not turning this on fast. I'm not using this as like a switcher. I'm usually like turning it on and it's keeping it on or turning it off and keeping it off. So I don't care the capacitance effects of how quickly you can turn on or off. So you have to pull current on off the the FET capacitor. But in this case, it's not that important. Okay, so let's go for a surface mount. So I'm going to find similar stuff. A surface mount active P channel MOSFET. There are some specs I'm going to sort of do manually. So let's see what we've got. My internet's a little slow, but hopefully we'll we'll be able to look it up. If not, I will just go to the Oh, here you go. Okay. All right. So let's look at what the specs that are important to me are. So first, I wanted to be in stock. Thankfully, the chip shortage has calmed down a little bit. You can actually get some parts. I don't want marketplace components. We'll have some not worried about. Let's see. So VGS, that's that was something that's important. And you can see that it quickly goes up to two, three, five volts, especially if you want the bigger transistors. But I want something again, roughly about a volt or less. So I'm going to select that. For RDS on, you can see they can get pretty high. I don't want like, you can see that there's some that are like, five ohm or more. I'm going to try to stick to 50. The one I looked at before that I'm comparing this to was 52 mil ohms. So I'm going to keep it nice and small. And I'm going to wait for this thing to update. All right. So now we're down to like 153 options. The drain to source voltage, you know, that's how much voltage you can switch. For this particular board, the feather, everything is three volts. You know, let me try again. For my feather design, it's three volts. But I, you know, I use this in my metros that are switching 12 volts. So I'm going to, I'm still going to stick with like 12 or more. I think eight's a little low because often I have a nine, you know, I have nine volts somewhere in my setup. 12 volts is pretty common. And then let me try again to apply. And you can see that there's a lot of SOP 23s. This is very common. Okay. So, okay, got those filters going. So the next thing is I want to filter out all the SOP 23s because, you know, the only thing is I've got about 150 options, 150 results here. And a first up is that DMG 2305. Again, that part that I would get the most of, I mean, there's tons in stock and it's, it's low cost. But I want to not have the SOP 23 size because it's too big. So let's go to device supplier package. There's also package case. I think I'll do package case. So I don't want a TO SOP 2303s or TO size chips. Chips are too big. I'll kind of pick everything above here because I don't want the BGA. I don't want the SOP 23 variant. I don't want the powered DFNs because those are kind of big. And I don't want the SOICs or T-SALPs. But I think the others are good. Let me see if those come up. Okay, great. So now you've got some smaller chips. So the thing is actually each one is kind of, they kind of come in like all different sizes and shapes. There's a few common sizes. If you go to the right, you can see the sizes. And some of them, at least they are pretty clear. Like for example, this one says two by twos. That's going to be two by two millimeters. This is 20 by 15, which is smaller. That's two by 1.5 millimeters. You know, there's micro fat. Basically, let's look at, because now we still have like 66 results. There's less, but it's still, you know, quite a few. Let's look at pricing at 5,000 pieces. So it looks like Toshiba has a couple really good options. Basically, you're going to pay 10 cents for this transistor, which makes sense. It's kind of a nice transistor. There are, you know, a couple different sizes, but it looks like two by two millimeter. Actually, it's not that much smaller than SOP 25. So what I did is I ended up deciding, you know, I'm going to stick, I'm going to deselect. So I'm going to select, I'm going to select all these, because these are the sub package types. I'm going to deselect two by two. So anything that was 20. So I was like, well, if I'm going to go 20, I might as well go with like a, you know, it's not that much smaller than SOP 23. So deselect all those. And then this is kind of getting intense. I've got like 15 filters going on here. Another thing I like to do is I like to filter by quantity and I go down. All right. So now filtered and now I, wait, did I actually do the filter or did I click away? Hold on. Oops. I did not actually filter one second. Maybe we do that filtering. So deselect the two by two. Sizes. Okay. Oh, I forgot to click apply all. That's why. All right. Let me let it chug. Okay. And then let's apply it. So I had a couple. There are a couple. There are two, two good options that I saw basically. So one, I liked this one was kind of nice up here. This is the UFM, which is actually kind of like a SOP 23 size, I think. And the, hold on. Let me check because there's still quite a few. Oh, I liked the SSM series. That was the one that was kind of interesting. So it's quite a few of these SSM series. They come in a few different sizes. There's also DFN 1616, which was nice and small. UFM I think is actually about the same size as the SOP 23. But what I liked is when I started like filtering by quantity available, this actually popped up, which is the DMG 3415 UFY. And the reason I thought this was nice is that I actually already use the DMG 3415 in SOP 23 in the same like situation, like it's one of my alternative parts that I've used. So this is just the DFN 2.0 by 1.5 version, which means it's it was basically like swapping compatible. It's just like shrunken down and has little pads. One thing to note though is compared to the DMG 3415, it's slightly less specification. Like it's not identical specifications. But a lot of the important stuff is like, for example, the RDS on is nice and low 40 milliohms. The threshold is one volt. The VGS is eight volts. The only thing to watch out for because I've used this before is that means if you're using it as an ideal input diode for polarity protection, the VGS has to be the same as the VDS. So just be aware, you can't use a transistor with eight volt VGS max with like a nine to 12 volt power supply. But again, for this feather, it's three volts. So I'm good. So I ended up really liking this one. And I specced it out and this is what it looks like. So, you know, compared to this is what the SOP 23, it looks like is how big it is. And then that's the DFN. So you can see it's like, you know, about a third of the size. The only downside is you can't route a trace through the middle here because there is well, not without putting down like some silk screen. You know, to end no stop. But this is the thermal pad. So usually you want to keep it open. Also, this gap is pretty narrow here and I actually made it a little bit wider. So you do have to have like a fairly, you can't use it with a rough PCB process. It has to be like seven, seven mil or six, six is better because of the gap is quite small. So I'm using this, I think it's going to work. I like that it's the same like core part number and it has almost the same specs. So I think this should let me make this design a lot smaller. I've moved that SOP 23 and the NBR054 up here and, you know, to the right here to clear up a lot of space and that let me move this crystal to the left. Okay, it looks like the tiny, looks like it has tiny side pads out possible to hand solder. Or is it way too small? You could solder this by hand, but you'd want to use a little bit of paste and hot air. Check out the last great search for where we cover how to get hot air in a syringe, sorry, pasting a syringe for doing this kind of hot air or hot plate work. Okay, that's a great search. That's right.