 The great search brought to you by DigikeyData for every single weekly data user power of engineering and help you get to find things on digikey.com and what is the great search of the week this week. I'm glad you asked. This week's great search is for a single channel level shifter. So let's go to my computer and I'll show you what I'm talking about. So a new product that I'm working on releasing this week is our new RP2040 prop maker feather. And this is designed to make it easy to do like very small, battery powered, portable robotics and metronics projects because that's always a good time. And on this board, I have like a whole bunch of stuff jammed over here. Some good stuff with the I2S amplifier. We've covered I2S amps on the great search. There's accelerometer, I think we covered accelerometer, the great search too. And there's also an output for neopixels. So on the bottom here, you can see that this is a Neo output. So a lot of people want to make props, especially like lightsaber type things, they want to have a string of neopixels controlled and neopixels, you can drive them off of 3.3 volts. But for the ultimate best glowiness, you want to have them running at five volts and you want the signal to also be five volts. Now, it is possible to do five volt power to a neopixel and give it data as 3.3 volts. But some older pixels don't like it. They kind of get a little flickery because, you know, the input voltage to trigger a high is usually 0.6 of the input of the power voltage. So if you had, you know, five volts and you're like, okay, a 0.6. You know, if you're 3.3 volts, you're above the 0.6 level there. And so you register 3.3 volt logic levels registered as a high. But what happens is oftentimes people are powering their neopixels from a very good power supply. And so the power supply has a little bit of a lift to it because it's meant to stay at five volts, even at very high current groups such as four amps, five amps, 10 amps. And so what happens is you get something that's maybe closer to like 5.5 volts of power to the neopixel. And then when you multiply that by 0.6, it's like exactly 3.3. And so your 3.3 volt logic level might work or it might be like 3.28. And it doesn't quite trigger. And so you get like kind of flaky behavior from the neopixel. Now, this is all covered. We have actually a learn guide called the Uber Guide. So Paint Your Dragon wrote an amazing guide that's been updated constantly about logic levels. And so it's actually 0.7. I say 0.6, but it's often 0.7. And so how you really should have a logic level shifter. And so on the PropMaker Feather, because you might be powering this from a USB power plug, a power supply that again gives you 5.5 volts, you want to have and the new the RP2040 is a 3.3 volt logic device, you want to have something that shifts that data out from 3.3 up to five. So, you know, some ways of doing it is, you know, if you're if you have infinite space and price is, you know, important, you want to make it super cheap, you can use two transistors, the first transistor inverts from, you know, zero 3.3 to five or zero. And then you have another transistor that does the second inversion, two inversions equals not inverted, and then you have zero to five volts. But I had only like a tiny little itsy bitsy amount of space left over because everything else here, you only came in one package, I couldn't get this, anything else, any smaller, the I2S amp was fixed. These power transistors need to be able to switch a lot of current. This accelerometer was a fixed package. So I really only had space for like a thought 70 in there. So what can we do to get a buffer in there? So let's go to Digikey and I want to find a non-inverting buffer. Let's see what we can get. So there's a lot, but not surprising, there's a lot of chips that do this, about 12,000. But let's let's try nailing down what we want. So here's the thing, we only need one channel. We only need that one signal converted. So first off, it should be active. We wanted only something in stock, only one element and only one bit per element. So it's like one, one, one. I don't need a quad or a hex level shifter. We did that actually on the NeoPixel 8. If you're interested in an 8 channel version, check out that guide. And that helps us reduce it greatly. Let's go only with surface mount. Not that there's a lot of through a whole single channel inverter. Let's do a buffer and a transceiver. A transceiver usually has a directional pin. We don't want directional. We want a buffer, not that there was, it looks like only one piece. Voltage supply. OK, so this is an interesting thing. If you are level shifting with like a logic tip, you want the output voltage that you will be generating, in this case, is five volt logic level. That's the power on the chip. Like, you won't be able to get a five volt logic level from a chip that's running at 3.3 volts. So we have to make sure that the power supply on this chip supports five. So let's only select the voltages here. This is like 2.7. This goes up to 3.6. This is 4.5. Not high enough. Now we're only looking at those. OK. Next, I want, I already kind of know what package I need. I need it to be small. So SC74, SOIC is not going to fit. TSOP is not going to fit. And I don't want any BGAs. SC75, that's, it's like SOT 23.5, but smaller. If you look here, look at this image. So these are SOT 23s, and this is a SOT 23.5. You see, this is like, it looks just like a SOT 23.5, but it's just like kind of here, that's a SC75. So it's like a little sister of this. The SOT 23.5 is SC70, also SC75, sometimes called. And there's just one that's small, the SC74. But I'm probably, you know, I mean, I'll show both. But I really don't want any BGA, and I don't want any smaller. I don't want a DFN. I want something that's very easy to solve or easy to debug with. So let's look at these. And then let's also look at only things that are in stock. And I don't want to look at Marketplace. I'll just look at what's in stock at DigiKey right now. Output type, I don't want open drain. I want either push pull or CMOS. Three-state, sure. You know, tri-state is fine, no big deal. And let's take a look at what we've got here. Okay, so now, scrolling down, it looks like there's, you know, this is going to be a lot of 74 logic. And as you'll see a lot of 74 logic, you know, there's like a billion families from all these different vendors. You've got Diodes and OnSemi and Nexperia and TI is going to have options and Toshiba and not NetSemi because they got purchased by TI. So we'll have TI instead. So there's, you'll see like a lot of like kind of duplicate parts here. But the next thing we want to do is figure out what series we want to use. So the 74 series is important. You can't, you have to think about what you're going to use it for and what the input is. So we want something that'll take a low voltage and shift it up. And again, remember that if the power supply is like 5.5, 3.3 volts won't necessarily trigger it on CMOS because it's not quite above that 0.6, 0.7 volts level that it's expecting for it to be a high voltage. In that case, what you want is to have a CMOS logic, but you want to have TTL logic inputs. And that means that anything above a one volt is going to be considered high. And that means we can do level shifting from a low voltage, even as low as 1.8 volt logic up to 5 volts. So for that, first off, you know, we're not going to use the bipolar TTL family because it's high current and annoying. And it's also almost impossible to get these days. We want CMOS family. So the CMOS family we want, we want something that can do TTL and we want something that does like fairly fast. So the original CMOS is fairly slow. We want AHC or, you know, advanced high speed, nice and fast, 5.5 nanosecond timing. That's nice and good. And we want, you know, has five volt tolerance inputs, which is no big deal because we're running at 5.5 volts. And then there is the T version. And this is fast and TTL logic levels. And it's also equivalent to the VHCT. So AHCT or VHCT will do great. I could also do a ACT. I don't know the difference between AC and AC, I guess is a little bit slower. So I think these are two good ones because the effect still can be, you know, it's fairly fast. So let's get some good edges on there. Look for the AHCT or VHCT family. So back here, we can search for series. So let's look for CT. There's AHCT, there's VHCT. Doesn't look like they have it. So let's look for AHCT series. Looks great. And let's apply. Okay, so now we're only looking at ones that will definitely work for us. So there's a couple versions here. So there aren't like, you know, different options. So one is you can use the 17 and the 17 is like, there's just one pin that's not connected. Honestly, I probably should have used this because there's not, you don't have to connect the third pin. You just have power ground input, output, you're done. You're good to go. Who cares? You don't have any signal select or anything. But, and then you can see the input high level is, this is AHC. Okay. So then we go to AHCT. Okay. So the HCT version. Hold on. HCT transfer. Okay. HCT 1G 117 high level output. It doesn't mention the input. How interesting. Am I in the wrong space? VI not mentioned. Well, we know from the description of the family that can handle input levels that are anything under like, I think maybe, oh yeah, negative going threshold. So for this, it looks like anything above two volts is going to be considered high versus anything that goes below 0.5 volts is negative is low. So this is fine. And then honestly, you can use this. Let's look at just pricing real quickly. The cheapest is going to be the HCT 126 or the 125. They're both about five cents. I believe the difference between the 15, 125 and the 126 is this is a output enable low. So you pull it low to enable the output. Whereas the 126 is output high. So the, you know, this, there's just extra pin that you can use to make the output tri-state. In this case, you know, we don't actually use it. However, it's not a big deal to tie the pin higher low and you're stuck with the package anyways. Like they don't have a four pin sought 23 or sought 70. You can only get it in five pin. So given it's extremely popular and available, I would just say and, you know, you're not using the tri-state, but maybe don't want to use a tri-state and some part in the future. The HCT 126 or the 125 are both going to be great. And like, wow, there are 706,000 stock. Hey, remember when we used to do these and there was like four, like we'd actually have to find something that wasn't stopped. It's like, it's like a distant memory. So 700,000 of these plenty available for you to do your logic level shifting. And of course, this part is also available in different packages. If you want, like again, I want to sought 353, but if you are looking for different package sizes, it's also available in sought 235. So a bigger version is available as well. Also for like seven cents a piece from a variety of vendors. So this part, the 74 HCT 126 is my choice for the great search. That's great search.