 and welcome to Desk of Lady Aida. Hey everybody, and welcome to Desk of Lady Aida. It's me, Lady Aida, at my desk with me, Mr. Lady Aida on camera control. Hello. And the scene's hello, Mr. Lady Aida. It's a wonderful, warm August Sunday night and we're ready to do the desk. We have 20, 30 minutes of some things I've been working on, some things I wanna talk about. This is my time. And we'll also do the great search at the end. All right, so I kick it off. I just wanted to say, you know, we went outside. It was outside. And we went to go see inertia in Washington Square Park and inertia is a really neat, like pop-up STEM thing. We met Karina and they have this cool mirror in Washington Square Park. It's there all day, it was there Friday, Saturday, Sunday, today, and I think Monday and Tuesday it has this mirror for young people to walk up in front of and it has this thing and says this is what an engineer looks like. And so it's a really powerful way, I think, to get young people to see. And a lot of people taking their photo in front of them. Yeah, and it was just like, you know, it was beautiful outside and like, here's Karina, there's Alexa, the photographer. And it was just really neat to see so many people going up in front of the mirror and they were imagining themselves with the word engineer and themselves. And I think this was a very subtle but powerful way to get people to think about. Check it out, if you're in New York City you can go visit it, Washington Square Park. It's there from like 10 a.m. to 7 p.m. Yeah, that was cool. We'll see you next week or so. So, we won't there. Anyways, so next up, a lot of folks sent this in and I guess I could start, just jump right into this, right? Yeah, jump right in. Okay, so this is one of the boards that we have and well, we watched Suicide Squad and Lady Aida saw a frame go by and she's like, that's my board. And when we looked really close and I had to like take a photo of it on my iPad because there's no way to screenshot. You can't screenshot, we're watching. So anyways, so she spotted it and we paused it, we got it and then a lot of people started sending us this. This is King Shark holding it in his peace maker but then I guess the marketing side they published this little video on Twitter and I'm gonna play just like a couple seconds of it but it shows our board, so I'm gonna play it. Peace maker. Yeah, so that's it there. Isn't that cool? Meme'd. And so you were saying, I could spot my boards anywhere because they look a certain way and I'm just like. And like two frames, it was very, I mean like, you know, hindsight wasn't that fast but you know. I should also mention that, yes, we're gonna try to make a 3D print star and use it all the way. Anyways, back to this. So yeah, so you were talking about, this would be a good thing to talk about on Desk of Lady Aida. Yeah, I thought it was interesting because it's like, you know, we were wondering, you know, what, we were making a joke, it's so easy to spot our boards because our boards look a certain way and I realize that they have a certain look to them. Yeah, like this went by fast. It was, it was, it's a split second frame. Yeah. And literally split second. I thought I could show, maybe on the overhead, maybe I could show some of this like classic Aida for design and what, what to look for what I look for. So, you know, for many, many years, when, I have to run out of time to use this thing. Why can't I? Take this. Okay. For many, many years, you know, I was making boards with green PCB mask like this, this prototype here is green. Green is the most, you know, generic, most common PCB color because it's the opposite of orange, we just copper and so you get really good contrast and so you can see the traces really well. And I think also the green LPI, they've just, I don't know, they figured out how to get really good quality out of it. I know when I did fabric silkscreen, they were also blue or green. There could be just some, something about that color that when you use a UV process to photo etch it, it looks really good. So we used green for a really long time because that was the most expensive, but there's actually a couple standard colors for PCBs. I don't have, you know, one of each color here, but I can show, you know, here's an example of a red PCB. This is just like a LCD module and there's green, there's blue, and then there's black and then there's also white, although I almost paused it. Oh, yeah, I did have one white PCB. And there's also sometimes you can get pink or purple and sometimes you can get yellow and those are the standard colors. Like not every color is available. There's white, black, red, green, blue, and then again, you know, sometimes yellow and sometimes purple, like Oshpark does purple. And when we were starting out, SmartFun was red, they had all their PCBs were red and I wanted to have our boards stand out and look different. And so I was like, I didn't really want to make them red, although sometimes they use red. I mean, like there's only five colors so you're, you can't not use a color if you own the color. But I wanted to try something different to make our board stand out and so I could sort of differentiate if I saw a pile of boards, if any of them were ours. And I kind of liked blue, you know, black I liked but blue I kind of preferred for a really long time. Also my PCB house had blue as an option that wasn't, they didn't charge more for it. And so I like blue with, you know, gold, enig coat, you know, the enig coats a little bit more expensive, but if you're doing pick and placing, I find that the vision system and the paste works better with enig gold coat. And then one of our developers K-Town kind of came up with his style, which he brought, which was to have these gold mounting holes, you know, these two 2.5 or three M3 metric holes in the corners for mounting a PCB. And so, you know, we don't always have gold plate on the PCBs, although, you know, here you can see these are plated, these are not. You can see that these, these have four plated holes. I like the look of the plated holes. They also, they're also visually very striking. And so people know like, okay, that's where I'm going to attach to. And the gold also gives it a little bit of strength. I think it looks better than just like a raw hole. Also, it tells you where the screw head is going to, you know, if you have a pan head screw, it covers the gold. And so like you kind of have an idea where PCB parts have to be away from so that you can use a pan head screw. So here's the question. It's not about our boards, but it may be a general tip. Does anyone have a good idea on how to work with an old PCB where the pads keep falling off? This person lost two boards already. Not eight of her boards, but general. Yeah, I know, if it's, if they're not meant for real work, especially the paper phenolic single sided boards that used to be, you just have to have a really good temperature iron and just work fast. And just, yeah, we do a lot of repair. A lot of people repair the boards. And then recently, we started doing black PCBs a lot for our designs. So, you know, here's a cutie pie with a black and white PCB. I don't know exactly why we moved to black and white. I think, you know, the original price that we got the ideas for the black and white PCBs was liquid wear. They were definitely out of business. And so we were like, well, you know, this is a kind of a cool look. I think like, my PCB house did not do black, so I had to find a different one. I'm like, I don't remember exactly. Yeah, it was harder for us to do black. And once we were able to, we did also, if there was someone else that was making similar things, they're like, well, let's try not to do that. And so, as soon as that was all true, we started doing it. Yep, so that's kind of the look. And so, you know, when this PCB was in this movie frame, it was really easy to detect it because it had the blue with the gold and those plated holes in the corner. And then, of course, the white silk screen on top. I still do like the blue. I still do blue PCBs once in a while. But really, it's those gold. It's like, what was it that really made me be like, okay, this is the thing. It's those gold plated holes. Those are kind of an aya fruitism. I don't see, I don't understand why other companies don't do it, but I think it's always nice to have four plated mounting holes. They don't take up too much space, but they show that it's not overly crowded. I've seen overly crowded PCBs with no mounting holes. And people are like, oh, I like the PCBs when they're small, but I think you don't gain a lot from having it that much smaller. Okay, let's now go to the great search. Yeah, okay. What do you want me to pop right in? Well, are there any other questions about PCB styling? You're good. Do you like the purple Metro M4? Yeah, I did. I'll tell you, I have done purple, but getting purple is a real pain. It's easy when it's through Oshpark because it can have a special deal, but getting production PCs, I've gotten slightly different colors each time. It's not as consistent as the black or the blue or the red. Those are very standard colors. I think they come with that color. Anything, you can get Pantone matched, but it never, it never quite looks as good. I would love to have X-ray style, the Oshpark X-ray, but I've had trouble getting a PCB house to do that for me too. So we tend to do black and white. All right, so do you want to belt right into the great search? Yeah, let's go to the great search. All right, the great search brought to you by Digikey and age for it. Thank you, Digikey, for making this segment possible. Lady uses her powers of engineering and her decades almost now of using the Digikey site to find parts you need. Kind of important now because it's hard to find some parts. Yes. So theoretically, if someone was looking for a part, maybe this week we're gonna help them figure that out. Yeah, I take inspiration because I think the people, what people are publicly talking about is what people are privately struggling with. And we had that quote from last week for the article where I think we were quoting about how hard it is to get parts and it's a struggle and like things get delayed. And also we mentioned the great search was a good place to go. If people have questions, go to Discord, tell us what part you're looking for and we will help you. So this week, let's go to the computer. So we got this notice for a crowd, you're a crowdfund backer of this project, this is the Glasgow Interface Explorer. And I thought this was interesting because they were having problems having a part. And I thought like, I'm not saying I'm going to find that part, I'm just saying, here's how I would go about trying to find the alternative, how I solve it. And I'm sure they have very good reasons for the reason they're doing what they're doing. So this is not to say I know better than them, I'm just taking inspiration. Yeah, so anytime we see anyone talking about parts, we're like, oh, how will we get that? Yeah, I'm using it as a basis as a springboard. So the last missing part that they have is a TPS73101 DBVT LDO voltage regulator for a GPO bank control. They ordered it, they can get it, and then like people are like scalping it. And they're like, we're looking for parts, but the TPS73101 is a pretty unique part. Besides the worst polarity protection also has fold back current limit. And that's one of the things that they like. So they like that there's this back current limiting capability. So I thought that was interesting because I never really expect a board with that part. And I do want to mention, so if you go to the TPS78101, sorry, 73101, which of course is not in stock here because if it wasn't stock, they'd buy it. So this part, the fold back current isn't something that's listed in the specifications they have over current, over temperature and short circuit and worse polarity, but those are like additional product features. Those aren't things that you can select for. The Digi-Key search is really, really strong when you're talking about quantitative qualities of your chip. So you're like, what's the input voltage max? What's the current output max? What's the inductance? What's the queue? What's the ESR? All of these things for your components, that's where the Digi-Key search is really, really great. But when you're talking about qualitative things where it's like, does it have this feature? That's where it's gonna get a lot tougher because it's not something you usually look up in a data sheet. Fold back current, like I said, it's not in there. Like you might say, well, that's short circuit protection or over current protection, but it sounds like it's a very specific capability that they're looking for in this regulator. And so that's why for this, if I was willing to find an alternative for this part, well, first off, you know, this part is a SOP 23.5 LDO. Having dealt with SOP 23.0 LDOs, this is a very standard package in size. So anything that we've, regulator that we find, with this package overall, the pinout's gonna be the same because like every SOP 23.5 regulator I've ever seen, I mean like, of course, check the data sheet, but it's, I've never seen one that doesn't have the exact same pinout from one to the other. It's a very standardized pinout, thankfully. Not always true. Your transistors don't even, there are only three pins and they don't have a standard pinout, but this chip does. So yeah, so this part is, you know, not available and they're like, we're not gonna have any till 2022. Maybe you don't wanna wait till 2022. So this is actually where I would go to Digikey, sorry, to TI, not to Digikey and look at what TI recommends because one thing that I know from working with TI parts is they often have, they often section out their regulators into capability slots. So for example, let's go to like, we have like the TPS, TPS 61023. So the 61023, this is like a boost converter. From what I remember, this is part of a family and it was like the 61023 and 61021 and et cetera, et cetera. There was like a family of them. Hold on, let me see if I can find it. I think it's, if I search for the TPS 61. Yeah, so there's always gonna be like within that part number, there's usually like a family of parts. So they'll start with the first two numbers, but then like one will be like a two amp regulator and one will be a four amp, one will be a three amp. So you'll be able to get like different levels of output based on like the part number, but it won't be like a sub part number. I'll actually be a totally new part number. So what I mean is like, if you're speccing a, when TI makes this boost converter, right? They make a boost converter and some are just gonna make it through the process and be able to like handle four amps, some are gonna handle three amps, some are gonna handle two and then they'll bend those and they'll separate them or however they decide the process. So you can get a two amp version, a three amp version, a four amp version. So this is actually also in the power boost. So the power boost 500 and the 1000 actually use, if you look closely to here, these actually use almost the same exact layout, the 500 and the 1000, but the chip is the same package as well, but this is the TPS 61090. This is TPS 61090 with a two amp switch and the power boost 1000 is the TPS, sorry, hold on. This is the TPS 6130. So the TPS 6130 is the one that has four amp internal switch. The TPS 61090 has the two amp switch. So the smaller number has the more current. That's how it goes sometimes, doesn't mean anything. Okay, so the upshot is, is that if you're trying to find a regulator or a boost converter or something from TI and you can't find your exact part, you might be able to go up and down in either accuracy or current output or like voltage input limit and find something that has almost the exact same capabilities, but like a slightly different specification. So if we go to, let's see, was the TPS 31, 73101, the DBVT is a sub part number that usually specifies the temperature, the packaging and the reeling, like how big the reel is. So we can ignore that. So this is, yeah, since this is part of a family, there's the 73101, which is the specific component. And then this one has adjustable output. And there's also the family, TPS 731. And this is, you can see, this is like doesn't have the full part number. That's cause it's a family of regulators, including ones with fixed voltage output. So the 101 is the adjustable, but then there's like the 73118, which is 1.8, 73150, which is a 5.0. Well, there's a wide range of them. But you're gonna have the same functionality like that fold back over current protection that they wanted, is going to be in every part of that family. So I thought what was interesting is that if you look, they have a range of very similar boards with similar performance and probably the same kind of functionality. So let's look at, let's look at find other, do I wanna find other regulators? Yeah, let's do find other regulators. Let's see if they have the fold back protection as one of the output capability. So this is 7313, VNMIN, let's not have a maximum output. So this is, I'm searching for the 73101 and then I'm just kind of deleting things that aren't as important to me. So no, the VNMAX can be, I guess this is fine, this is fine. We can say maybe the noise is not as important. I don't care about fixed output because I want adjustable output. Let's remove the VNMIN so it can be a wider range. And VNMAX has at least five volts, VLMAX, yeah, five volts, that's fine. And then the minimum as well. Okay, so it has about 13 different parts and you can see that this is that 73101, it's still here. Oh wait, we wanted to find the fold back. Let's see if this is in here. Actually, I don't remember if this is in here. Okay, here you go, fold back over current protection. Okay, so here's the ones that have that fold back protection and have at least maybe the same amount of current. So there's the 73101 and there is the 732. And if you look and compare between the two, the 731, 732, both have the same list of functionality. This one's a little bit more expensive. This one looks like it has the same number of fixed outputs as adjustable outputs. And this one is 250 milliamp output instead of 150. So that makes sense, the 731 is 150, 732 is 250. So if we look at the 732, now again, if I had more time, I'd go through the entire data sheet and I'd compare it one by one to see if the quiescent current is what I need, if the drop-off is what I need. But it could be that you could just use this instead of the 731, just use the 732, the next step up. So if you go to digikey, I think TPS 73, 732.01, because the 01 is the adjustable version. And let's also only show in stock because we only care about if they haven't stocked, that's what we're looking for. So it looks like there's two versions. So for, I don't know what DCQ is, I don't know if this looks like it's a different package, although that's weird because I didn't know this came in another package. But they do have the SOT 23.5 in it. It's available through a marketplace, it's through a third party. Rochester Electronics sells, it's gray market, it's not the official distributor, but they do sell distribution quality parts. Looks like they've got 3,000 available. The only thing is the price is kind of high. It's gonna be $2 instead of what you would normally budget for it, which I believe in the search set a budget of about 50 cents. So the question is, is the extra $1.50 price worth it to get this board out there on the road? Another option that I would do is if you don't want to go with the TPS 73, 201, there's also the 73 401, which is the next step up in linear regulators. And this one was also only show in stock. And this one, oh, this one, yeah, you can get these a little bit cheaper. They go down to like a dollar or 73 cents, but they don't have a lot in stock and they're not getting them talked over. So nevermind. I thought that they actually had some leads in stock, but if you can find through another distributor, you could also change to the WSON version package. I guess they come in both SOF 23 and WSON. But I think the best bet right now, you know, it's annoying to pay more for a, whoops, one second. It's annoying to pay more for a regulator when normally you'd spec of 50 cents and you're paid $2. On the other hand, it's $2, not $5. And if you really want to get it out the door, this might be more important. And maybe next time we'll also look at maybe how to find other regulators with foldback current protection. Because again, it's a unique thing that you're gonna have to know how to find. But this is a good alternative. You know, if you really want to get your board out and you don't mind spending a little bit more, I think this would probably be a drop in alternative. And of course, you know, it has more current capability so you can even connect more stuff to the output of your board. All right, that's a good church. Where are you? Oh, I forgot to do my disclosure for all this stuff. So we don't get paid to write about Warner Brothers movies, we're not part of the Suicide Squad yet. No, we keep applying but they don't do this. We saw the movie on our iPad and we saw this and we write about stuff meant, our stuff is in the Mandalorian and a whole bunch of others and it's always really cool. Yeah, our stuff comes in movies. It's always really cool to see your stuff in movies and we're always gonna write about it and we don't do any marketing for movie studios or whatever. So please do not have bad faith arguments about that. It's not true. That's my disclosure. It's mostly just Twitter. People are kind of nuts. Okay, that's. All right, that's it. We talked about some board designs, we talked about some alternative parts and we showed some errors. All right. Thanks everybody. See you everybody during the week.