 The great search brought to you by digikey and and a fruit. Thanks to key lady Ada user power of engineering every single week to find the things you need to find On digikey.com. What is this week's great search lady? Okay, so this week's great search is related to the board I just popped up on the screen This is the board that I designed a few weeks ago. It's the PC a Or TCA 9584 a this is a STEM a QT version the plug-and-play version a very popular eight channel Multiplexer board that we have so you have I squared C chips as you know They have addresses the address that can't conflict if they do conflict then either change the address Or you can use a multiplexer in the multiplexer. It's like you have to like tell it You know it's over I squared C's you spent send like one special command to the address You tell it which to connect to and then it'll reroute the signals and it does it transparently and it does work Pretty well. I think there's a couple of weirdo chips that don't like multiplexer smoke for the most part They're a great way of just like hey, I need like that light sensor the LTR 30, you know 329 You're like well, this is a really cheap light sensor But I need to have eight of them in a grid You would use something like this so I was designing this but as I was doing this I thought it would be a Good idea to not just have an eight channel version But a four channel version and so because some people like well, I don't need something that big I want a little smaller board But again, I don't need or maybe I want like all the pads broken out, but I don't need Eight channels for us plenty and I agree it is a lot like most people don't need eight channels so it's gonna computer and See how I did this because it was a little bit weird to find and I'll show you why so this is the TCA 9548 and so what I usually do, you know, people know that when I'm looking for Oh, this is by the way that lights up to the LTR through 29 as you know, I'll type it in and Then I'm like Cool, let's find the the chip. It's well Let's find the chip itself and there's a valve boards and there's a valve boards But then I want this Multiplexer decoder and I'm like, yeah, like this chip. This is the chip I'm buying and set of stock I want like the four one by four one So I want like an active bus switch and I want to be surface mount and then I'll just select when it comes up with the Search thing I'll select one two four by one. So, you know, I did that and When I looked like there were a couple options, but I kind of had this feeling of like maybe there was something else also They were a little confusing like some of these they weren't like I squared Well, some of them were I squared C. This one was But I think like this first one The maybe wasn't trying to remember what it was some of them were like they weren't quite I squared C compatible Yeah, like this was like a different kind of switch and I was like, well, I don't know if this is Yeah, this is a bus switch and that's cool, but I wanted like an I squared C multiplexer switch in particular and No, let's go back So I was like a little bit confused because like really this is all there is like that doesn't make any sense And they realized that there's actually this chip is such a weirdo chip It actually get categorized in a couple different locations. And so I was like, oh, you know, I should show people That yes, you can always search by using the did you keep find similar? but there's also a lot of reason to go to the place where you the Chip fab the maker of the chip and use their search because oftentimes they'll find They'll have all the parts and you can have a slightly better search for their products The only thing is of course, you won't find like competing products So you have to kind of do this for every company that might make something similar And then it's like well, how do you know what companies might make something similar and the answer is like You don't really maybe you just like do the best you can like think of you know Is this something that ti would make is it something that analog devices would make is it something that? Maxim or like, you know Renaissance would make so in this case the PC a So the TCA 9548 And you can see here that this is the breakout board remake. It's actually this one's made by ti So you actually go to ti's site and then you know, they have the there Look, did you he has like a you know five bazillion literally different Chips and companies and it's hard to sometimes categorize them Exactly, whereas like ti has a lot of incentive to categorize all their products very well because This is their job like their job is to sell their products to make it easy So for them, they have a whole category called I squared C multiplexers and switches and then what's nice is that you can View all products and we'll say because my monitor isn't that big that this works best in like 1080p And this is 720 so you'll see a long, you know, it's a little easier to navigate these massive tables Okay, so that said you can see here that they have a lot of options and of course will have the automotive and the catalog type They'll give you the approximate price, you know, which is very optimistic But let's see what we can do so number of channels And you can see they have a couple options here for Let's see. Do they have a number of channels? I Think oh, it's not added to the search. So we have to click on it and now it's added so number of channels So basically how many I squared C to you know one to X and we use the standard the TCA 9548 a which has Eight channels when we want something with four so we can go down to here and say we want it to be No less than four no greater than four and this will give us six options So then the other thing is you can look at the package group, you know I do like Q of fans the most Q of I mean SOICs I find to be a little bit too big But if you're a beginner, of course, they're hand-solderable T-Sops I find annoying They're hard to rework and they're hard to pick in place. I'm not huge fan of T-Sops I like Q of ends the most. I find them fairly easy to rework You can there's no pins to bend and they're also very small, but you know, everyone has their own favorites So you can search by package group. There's another you can search by supply voltage And one thing I noticed as I looked at this is actually there's two. There's six There's six chips, but there's actually Three chips two variants of each. So there's the TCA 9544 and the PCA 9544 and the difference is one the number of packages, sorry the number of packages available so the That I don't want to click this because we'll pop open. The TCA 9544 has only T-Sop Whereas the PCA 9544 has T-Sop, V-Sop, Q of n and that's because the voltage is a little bit higher supply voltage So, you know historically we used PCA Sorry, we used TCA which goes down to 1.8 volt logic But one thing you have to decide is especially with a chip shortage is like maybe you're okay with Something that has slightly less voltage restrictions. So I was like, you know what I only need it to be 2.3 volts minimum. I don't really need the one point You know 1.65 I'd rather have a smaller package And then there's three options and so then you can look at the difference one is addresses which is How many like address pins you can set and I do like having You know some address pins and then there's the question of whether you have reset or interrupt or Reset and interrupt and you kind of trade-off if you want reset and interrupt you you lose the addresses I like having the addresses. So then the questions with which one I wanted the the reset or the interrupt pin The interrupt pin was interesting You don't go into the details, but you can look at the day She basically for each of the four channels you can have an interrupt line And there will or them for you or you know, whatever to get you One interrupt output, which I was sort of like I Was not as interested in because again, it's gonna be like stomach you teapot So I kind of ended up deciding. Okay. I want the reset pin with the address. This is the 95 46 a Remember, there's the TCA and the PCA version depending on You know whether you wanted the 2.3 or 1.65 voltage and then I just went back here and I typed in that that that half hazy and There's some of decoders here, but was interesting. It's a cat interesting There was kind of like a mix and match like they appeared here But they also appeared under interface specialized and This is where the actual stock was so there's actually a couple pieces in stock nothing is NXP and and TI both make the same Almost exact part number. I don't know who made it first. So You know if it's NXP and TI, you know made a version or the other way around I don't know but they seem to use the same Part numbers and they do have in stock the well, let's go to the active ones just to make sure that we're Only looking at what's available They have the TSAP version the SOIC version and of course my favorite is the QFM looks like TI has a version in QFM and they're not in stock right now, but NXP also does there's also a VQFM. I'm not Not as much in love with a VQFM, but I do like this one. So I'm into this This part since the part I'm gonna get samples of again, it's nice and small but easy to rework I love, you know, if it's as long as point five millimeter pitch I'm really into QFM and then as a side note just because I'll wrap this up But this category interface specialized is super freaky weird and cool like there's all the weird stuff that doesn't really fit anywhere else and I just started like clicking around in some of these and they're all like really kind of cool. There's just like weird like Display port to VGA converters from analog devices and like multiplexer things and like like what is this? TDP Something something This is like a 8 gigahertz linear redriver for display port like it's just like the weirdest Stuff so I do recommend checking out This zone I sorted by what was available and I just I just found some really funky weird chips a Lot of them are in the marketplace like some stuff got released into the marketplace. There's some You know bunny had a post about how he thinks there's some cancellation of components, but Yeah, do check this out. It's just it's just weird It's just weird chips and I kind of love weird chips. Anyways Uh Where was I right the PC a 95 46? This is my pick For this week's the great search. That's a great search