 and welcome to Slaida everybody and welcome to my desk. It's me, Lady Aida, and it's hacker o'clock, eight o'clock, about 8.30 on a Sunday night. I've been working a lot actually this week because the weather got a little colder. So a little bit more indoors, working on some new designs and revisions. And I thought I would just get right into it and show you some of the board designs that I've been up to this week. What are we doing? Where are we going? It's got a computer, sorry. So first up, you know, chip storage is not over. You know, nothing ever ends. But there are more parts available. Oh, you know, dude, I forgot to set this back to 720. Hold on. Oh yeah? Yeah, one second. Okay. I was like wondering like, why is there so much space on my desktop? Okay. Usually we don't see the text a little better now. Right. So some chips that are back in stock, not everything. So don't worry, the great search is continuing to find replacements for all the parts that have been end of life or discontinued or still unavailable. But there are some parts that are available. So the SI 5351 clock generator, people really like this chip. It's really fun because you, over I squared C you can tell it to generate, I think like up to 160 megahertz signal. So ham radio people, RF people, but you just people who are like, I just need a clock of like some freaky ass amount. You can use their calculator to generate basically any frequency from eight kilohertz to 160 megahertz, which is great for reference clocks. So, oh my goodness. There's so many boards, so long. This is the TPS. This is the, I gotta find it so I wanted to show you guys a bunch of things. Okay, so this is the design. Let me turn on the T-document layer so you can see what's going on here. So I decided to take QTFI this design. I'm still gonna sell the three SMA version, but I thought I'd make like a small version. A lot of people only need like one signal or they're popping this into a dev board and maybe they don't need something as big as, you know, like I kinda wanted to find some alternative to just having one gigantic board with three SMA connectors. So this is a QT and it's got the level shifting. I just picked a smaller crystal, so it all fits. Same chip, level shifting. And then what I did is this kind of like funky design where there is this edge launch SMA, but they have point one in spacing. So what I ended up doing is having like signal, ground, signal, ground, signal, and then only the signal number one, the middle one is SMA edge launch. Cause again, there's no mechanical space to have more than one edge launch RF connector, but I think that's okay. Cause I think again, a lot of people need one signal and if you need all three, you pop in a breadboard and then of course you get interspersed ground, which is even better. So this is a prototype. You can see, you know, the pads will be just really big here, but otherwise this will be a fun little STEMI QT vacation. Okay, so then next up, let's go in order. We made the Metro Mini V2 a couple of weeks ago, a couple of months ago, and it's in the store. Folks who remember, it's got the Mega 328P and then there's a STEMI QT connector and the STEMI QT connector is five volt power and logic. And eight of its STEMI QT boards are three or five volt compatible, even on that SI 5351 you just saw, there's always a regulator and there's always a level shifter. And it's like, it's just kind of my thing. I really, I don't like breakup unless there's some really good reason I like my breakup boards to be level shifted and power protected because there's still a lot of people using Arduino UNOS, there's a lot of beginners who they accidentally put nine volts into the power supply or whatever, having a regulator and level shifter just protects you a little bit. Just like it would be such a bummer to destroy a $15 OLED because you accidentally put five volts into three volt line and I've absolutely seen that happen. So all of our breakup boards have level shifters but if you're using like quick boards or some other breakout boards that have that JSTSH connector, they may not have level shifting. They may be three volts only. So I made a little board that just all it does is have the five volt regulator and level shifter and there's no chip. So it's like normally there'd be a chip or sensor here and it's just split in half where it's like five volts in, three volts out. So it's gonna be like really inexpensive. It's gonna be a couple of dollars but if you want to breadboard with STEMI QT connectors and have level shifting, this does everything for you. It's kind of like breadboard adapter slash level shifter slash floor polish slash dessert topping. So very simple little breakout board but I thought would be very handy and you can see that nice silk screen because we now of course have the penguin script that we run on boards to make them very pretty before we get prototypes made. Next up, another QT vacation. I haven't run penguin on this one. The ADT 7410, this is a very nice precision temperature sensor from analog devices. This was one that we did as a partnership with DigiKey and ADI but it's a very nice chip. It's like literally the last sensor we made before we started making everything STEMI QT-ified. It was just like, you can see, it's got like that same like shape and size but it didn't quite make it to have the JSTSH connector. So we're gonna revise this one as well because this chip is in stock. So when we sell through, we'll stock the STEMI QT version just trying to get everything into the same format, same pin order, same connectors just for, you know, cross compatibility, no soldering support. So that's the, you know, this is the ADT. So the only thing I had to drop is the address pins are now jumpers on the back. You know, that's the trade-off when you go with STEMI QTs. I really like to have those four mounting holes. I just think it makes it much more useful for people because you can like turn it into a wearable by sewing the four corners or if you want to attach it into a case you have many, many options for where to attach to. But, you know, I had to drop the address pins but usually you don't use the address pins. Usually they're on the back and you solder them closed on the off chance that you need to change the address. So that's the ADT, temperature sensor. Next, I'm gonna go out of order. So the pi cowbells, or Picobells, these, I got a little distracted for a bit. I know we designed these a few months ago and I was like, no, I'm totally gonna do these. And then like, I ended up just getting totally distracted with a whole bunch of revisions and new products and stuff. So as a reminder, we can go to the overhead. I can show the previous version because I did get the prototypes in. I wanted to start with making, you know, boards for whether you have Pico. So I always start with a prototyping shield because it's kind of like the, you know, it's what I use then to design the rest of whatever I design. So with this, it just breaks out all the pins. You can barely see the text, but there's, you know, there's label text. There's these white stripes on the ground pads. So you know, cause like the ground pads are how you count the pins. And then we also soldered a little, you know, this, I put this one together and I put it with stacking headers. And then there's a right angle reset button because I figured that would be kind of nice to have at the end. But then as I was working on it, you know, working, I was like, oh, you know, I really want to, especially when the Pico W came out, I think a lot of people want to add sensors very easily. And, you know, if you're gonna have this prototyping shield thing, it would be really cool if it also had a stomach UT connector, but there's not a lot of space on this. So what I ended up doing, you can go to the overhead. First up, I changed the, sorry, the computer. At first off, I changed the through-hole to a surface mount right angle switch, which meant me, you know, I had a little bit more space for text here. And then I wanted to have a stomach UT. Now I couldn't have this and the button on the same side. There's just like literally, you can't fit them next to each other without dropping some of those pads. And I don't want to drop the breakout pads on the most useful part. So the stomach UT actually comes out the same side as the USB connector, which I think, I think it's okay. You know, it's a trade-off. I think, you know, if you're gonna plug in a cable, you're gonna plug in USB and then maybe you plug in the stomach UT, you know, you have just cables coming at one end. On the other end, you have the button. It's, I think it would be tougher if the button was like, if I swapped orientation, because in the button, you'd have to reach under the USB cable. So this is a stomach UT connector and it's connected to ground in three volts because that's the logic level in power supply. And then, let me find the thing. So in the Pico core for Arduino, they do have a default setting for what the wire port is. And it's on GPIO four and five. And so I actually just, I kind of just like said, okay, fine, you know, I'll just connect these automatically to four and five. So you see down here, GPIO four and five are pre-connected. I didn't add pull-up resistors because again, all of our stomach UT boards and all the quick boards as well have pull-ups. So also I just didn't wanna add, I think it's kind of like, this is, you know, people really complain they're gonna add pull-ups later. But I think for most people, they're using breakout boards with, you know, pull-up. You know, the pull-ups are built in and they'll pull it up to 3.3 volts. And so I think that's, I think that's fine. So this is the stomach UT port on this side and then, you know, those fuchsial. So it's gonna be a very easy breakout to make. And then, you know, we've got a little grid of pads here. You know, you can add other sensors or breakouts or, you know, you can't really fit a dip chip but you can fit one anyways because it's such a small amount of space in there. But maybe like resistors, capacitors, maybe like, you know, 0.1-inch header. So, you know, this cowbell is gonna be the first one. And then I'll get to the others. I just was like, I couldn't quite get into this big project. All right, and then, oh, we're getting close to done. Okay, so then, this is a, you know, solderless stem breakout board. You know, I have a couple of these for some things like relays, like, it's like, whenever there's a couple of things that people want to use together and I've noticed that it's, they wanna use it solderless, I'll make something with one of these JSTPH connectors, like a big chunky connector. For example, let's see, I think I have like a stem up relay board. So like this board, for example, you know, it's just a JSTPH and then a little bit of circuitry for say like running a relay. And I saw someone in the forums having an issue where they're like, well, I really want a very powerful infrared transmitter. And I was like, oh yeah, like you really need like a MOSFET and you know, like a power transistor and you need the LEDs and you want more than one. And it's like, it's actually a little bit, it's not easy to wire up. There's just a couple of things that you need to do. And so I thought, oh, maybe I'll make a little breakout. Could also be useful for accessibility projects where it's like, okay, I wanna make an IR blaster. And so this has, you know, power ground and signal. You can use three or five volts. It goes into this end channel FETS, which has a natural pull down. So it's, you know, normally off. And then when you send the signal, it'll turn on and pulse these LEDs. And I saw some LEDs that are like very, they're basically as powerful as the through hole ones, but their surface mount, one points up. So this is the vertical one. And this is the right angle one. So one points out, one points up because I was like, oh, you know, people are gonna want to have it, you know, cover an area. And it's always like, do you want it pointing out or pointing out? And I was like, well, let's have one of each. Who cares? They're like, you know, 10, 15 cents each. Each has its own resistor and it's just powered by this transistor. So very simple. And then a little LED to let you know when the signal, because infrared is not human visible. This would have a little red indicator to let you know, okay, there was signal received. So this is a simple little breakout just to solve that kind of problem, which I've seen a couple of times. Okay, and then finally, I made a breakout for the TPS61040, but also, you know, maybe a different one. We'll talk about that in a minute. You know, once in a while when you're using OLEDs or LCDs, TFTs, or like some, you know, there's sensors, once in a while you need a bias voltage of like 12 volts. And it's not like you need a lot of current. Maybe you need like 50 milliamps, 100 milliamps, or you need like a little bit of current or a little bit of current at a high voltage to like bias or enable some signal. If you're doing audio, sometimes like, you know, your audio amps, you need a 12 volt power rail. Even if your signal doesn't go up to 12 volts, you still need a lot of headroom. So we want to make a little boost converter breakout for this TPS061040. This chip is a replacement for another boost converter that we really used to use a ton of the FAN5331, but as I was designing a FAN5331 breakout, I realized that it's end of life. And so I had to find a replacement. So the TPS061040 is the one I picked. One of the ones I've picked so far, which leads us into the great search, but maybe there's some questions. No, let's just do it. The great search brought to you by DigikeyNator for Thanks, Digikey. This is the time of the week where ladies use their power of engineering to help you find the things you want to find on digikey.com. What are you looking for this week, Lady Aida? Okay, so this week, chip shortage is not quite ending. It's relaxing a little bit, but there's still a lot of parts that didn't make it to the other side. And one of those is the FAN5331. Now you might be saying, Lady Aida, you covered the FAN5331 a couple of months ago. I remember that you found an alternative for it. No, no, no. My friend, that was the FAN5333, which is the constant current version of this boost converter. I'm not gonna be looking at the constant voltage output version of this boost converter. The boost converter before was what I used for LED backlights on four, seven, 10 inch TFT displays. It's a big LED chains where you want to have a constant current of 20 milliamps through multiple chains of LEDs. The FAN5331 is what I use oftentimes for e-ink and OLED and TFT displays where I need a bias voltage, especially for OLEDs. This is very common. You need to give it a 9, 12, 16 volt bias to activate the OLED, even though it's not like the main power source. You do need 50 milliamps or so, maybe 20 to 50 milliamps available for all sorts of devices. As I just mentioned, sometimes audio circuitry also, you'll need plus 12 volts, even if you're not using a full 12 volts for your audio signal, the rails need to be hired because you need a headroom for your audio amplifiers and they go up to maybe six volts. So again, for biasing, this isn't a power, that's not what I would call a power boost converter, although if you only need 100 milliamps, then it'll do the job as well. So let's go to the computer and let's look at this chip. So the FAN5331, I really, really love this boost converter. 1.6 megahertz frequency, adjustable up to 20 volts that it has a built in one amp peak current switch and it comes in a SOP 23.5. This thing is like, it was a bread and butter, like I could toss into any circuit. It was, you know, all about a buck or less. I think we just, it did the job beautifully perfectly and they never blew up. They were super stable, low shutdown current, low RDS on, lovely, lovely chip. So you're like, wow, why don't you just buy more from Digikey? That's a great question. If you were to find this part on Digikey, you would see is last time buy. Last time buy means they will do one more run and then, you know, if you need a couple of years worth, please put in a couple of years worth that you need to complete your manufacturing until you can change over to another part. I will do a last time buy because I, you know, I like to have some backup for, yeah, sometimes you find an alternative and the alternative isn't quite perfect. You might as well put in that last time buy order. However, I've also learned sometimes last time buy means, no, that's a, we actually are never gonna send it to you. I'm looking at you, STMP 811, who's last time buy lasted two years and then I never actually got the part and then they told me they will never send it to me. So it does happen. Not say it's gonna happen here, but I've learned when I see last time buy, I find alternative immediately. So a couple alternatives suggested, but actually I wanted to, some of these might be okay, but let's use our patented search ability to find something similar-ness. So we want a DC-DC regulator with internal switches and one output. I'm not as picky about the internal, you know, the Min and Max input voltages again, it can be wider, it can be narrower. Basically, as long as it's three to five volts, I'll try to find something with about 20 volts, one amp switch and hopefully high frequency. I do want it in SOT 23.5. I want it ideally to be pin compatible and functionally compatible so I don't have to redesign. Okay. So, and then we're gonna get pricing at 1,000 pieces. So this is fun. This is the, you know, this image is not correct because this is SOT 23.5, but it's good to know. And there's a couple obsolete parts. Here's that fan 5331. So this is, you know, last time buy and then a couple others in that family you can see the fan 5333 is also last time buy. So let's, let's have a look at active and that'll cut it down like half. So only 30 options now. I also want to look for normally stocking only because of some of these are, you know, not, you're not available. I don't mind if it's a marketplace, that's okay. One thing I'll note is a few of these are step down. They're not boost converters like this one. This is a regulator and this is a regulator and they're step down converters, not step up converters. So we do want to note that, you know, you want to make sure you pick both SEPIC style and step up. SEPIC is a single-ended, something, something converter. Basically, you know, it's usually a buck boost. Sometimes you can configure, you know, by adding more trends, yeah, more shocky diodes and more inductors, you can kind of reconfigure it. So it's okay for the voltage goes a little bit under or above. That's okay. We'll just select both. The voltage supply max is fine. The voltage supply min, all these are fine. They all cover three to five volts, that's fine. And the voltage outputs are for these are also fine because they just want at least 20 volts. The current output per channel, again, this is confusing because there's output and switch. Usually these are specced by the switch, I will say. So that said, if you look at the switch current, you're not gonna get, you know, there is one that's 2.8 amps and it's like, wow, that's cool. But it's out of stock. It's the LM 3410, currently not in stock. So that's a little sad. Maybe I'll actually say only one will get in stock ones as well. Okay, so back here. So the current output channel. So, you know, basically there's 550 milliamps. That's kind of the max. So if that current output is important to me, the LM 2704F, it's a little bit more expensive. It's $1.25 on tape and reel. But, you know, it does do the job as adjustable up to 20 volts. You know, built-in switches half as much, 550 milliamps. Great for LCD bias supplies, what a coincidence. And then, you know, this is basically your classic circuit, which is the same circuit you'd use for the FAN 5331. And I do check the pinout. The pinout is identical. I can quickly look it up to verify for you. So it's switch, ground, feedback, shutdown, be in. And this is switch, ground, feedback, shutdown, be in. So one, two, three, four, five. It's in the same order and the same circuit. Although the feedback resistors may have to be adjusted, that's not a big deal. But otherwise, this looks, you know, very similar. You have to give it the shocky diode and the inductor and does the rest. So this one's good. However, you know, for a lot of the bias circuits, I don't need necessarily 550 milliamps. I'm glad it's available. And then of course, if I'm willing to spend even more, there is a version that has a built-in 2.8 amp switch. So that's good to know. And it's actually kind of nice. It's also 1.6 megahertz. Again, it's more expensive. The original Fan-Fi 331 was about 75 cents. This is a $1.50, but there is something available, the LM3410, so that's good to know. But for my purposes, I'm actually kind of okay with using, you know, 350 milliamp switch. So again, I only need like 10, maybe 20 milliamps at 12, nine to 12 volts. It's not a huge, again, it's not power converter. It's a bias generator. So I'm actually okay with this one, the LM2703. Right, because again, this comes in a family, the 2304, 2704, and then the 2705, all, you know, you pay more for the bigger switches. But this one does the job. And hey, it's in stock, hard to beat. But this will do the job quite well. Again, 2.2 to seven volts in, up to 21 volts output. Simple boost converter, it'll do the job, and then pin compatible. So I can just drop it in. And for almost all of my OLED biasing needs, this chip will work quite well. And that's a great search. Okay, okay, here's a question. When you have two or more IR LEDs, is there a possibility of timing issues with one being ever so faster than the other? No, LEDs are instant, essentially instantaneous. Okay, let me check the other spot. Do we have a graphic for a dying chip end of life? No, you know. You're a little halo on top of me. Yeah. Lots of heaven, you know, there's a place, they're all frolic on the circuit board in the spot. I don't know if I'm ready to do that one yet. We'll see, ask me next week. Okay, those are the late eight, we'll be doing all of our regular shows throughout the week. Thank you so much everybody for joining us this Sunday night. Thank you everybody, lots of live shows this week. Take care, stay dry.