Hi in a previous repair video linkedin. if you haven't seen it, I uh, repaired one of my failed aputure Amaran uh, hr672c Led studio lights and spoiler alert. I recommend you watch it first because it's quite interesting how I trace it down it's a failed mosfet and simply replacing the mosfet which I salvaged from a dumpster laptop which was pretty cool. I fixed the light so that was a winner winner chicken dinner, but I thought I'd do a follow-up video.

Actually, I'm showing you how when I first actually found this mosfet, I went to search for it. I knew it was a mosfet and I searched for it and I couldn't find any data on it whatsoever and I didn't recognize the markings on it. So I had to actually not only find the manufacturer, but to figure out exactly what mosfet it was, but also potentially find a replacement as well. even though in this video I actually got a replacement mosfet which is not similar specs at all um, from a dumpster laptop and it worked just fine which is excellent, but I thought what would be interesting to do is a video showing you a how to find that's how I found that specific manufacturer of that mosfet and then, uh, potentially finding actual replacement parts for it either the identical replacement part or a like an equivalent apart especially if the specifications matter because this just happened to be an interesting example of where it uses one of these, um, obscure Asian brand manufacturers you've probably never heard of if you just used to all your mainstream manufacturers for your semiconductors and it didn't have a typical type number on it so you couldn't just readily find.

Oh yeah, I can get one of those from Vishal. So let's take a look at the mosfet in question, shall we? It's actually down here. It is this bad boy here. Uh, it's got actually two numbers on it: 4303 and Rr6sa.

And if you're not familiar with parts, you might know well. which is the what is the part number? Is it the top one? Is it the bottom one? Is it? All of it tied together? Should you search for the whole thing, what would you search for? And then here's the manufacturer's brand over here. What is this one? And it looks like they've got a similar one up here, but it's a bit fuzzier and this one over here as well. Well, the first thing is you have to sort of give an educated guess.

You can go search for the part number, but the first thing is is you have to identify what actual component you're looking at here, but we won't get ahead of ourselves. Step number one is to identify well. What part is this? If you're not experienced, how do you identify that this, uh, failed chip here is actually a mosfet? Well, first of all, you look at the reference designator. In this particular case.

it's Q. That's a Q4. There's Q3 up here, there's Q11 over here, and Q is the industry standard uh designator for trend and transistor. So if you see a queue, you know it's a transistor sometime and some type.

So it could be a Bjt, a bipolar junction transistor. It could be a mosfet, a metal oxide semiconductor field effect transistor. or it could be a Jfet, a junction fet. And but Jfets aren't really used these days.

and for this sort of application for uh, Led lights, you basically you need these for our switching. In this particular case, it's actually switching the battery packs and things. But even if you didn't know that this sort of application you go, it's more likely to be a mosfet these days. They're more popular than Uh Bjts for like high current switching applications because the on resistance of these chips is much lower.

They're you know you can get like much higher power ones in a package and all the characteristics are around. It just mean mosfets are better for like switching, power type stuff, switching, you know, driving Leds and switch mode, uh, converters and you know stuff like that. So it's most likely if you see a queue in this sort of application most likely going to be a mosfet but there is another way to tell and that's to get it at the right angle. sorry this.

uh I didn't take a specific photo for this. I probably should have but you can see up here that let's have a look at the one at the top. you can't see it as well. Down the bottom, you can see that look.

There's a huge big track here. These three pins are actually shorted and you'd be able to measure this with your multimeter as well. So it's got three shorted pins here. And the and look, this is just one trace here on this side.

So all four pins on this side are shorted and this one, you can see a trace just going off there like that. And this for an S08 package that we've got here. this is a classic pin out for a mosfet and the other reason you know it's a mosfet because generally you're not going to get a Bjt transistor in an Sl8 package like this. In fact, if we go over here and we search, you just search for Bjt and then I went in the search for single uh, Bjts and then you go over here to package uh, package case over here and you scroll down and scroll down and look.

We can get some eight pin soics, but let's see how many of those we get. Yeah, one basically. Um, and there's zero stock and it's obsolete. It's like, yeah, you don't really get Bjt uh, transistors in an S08 package.

So that's you know once again. another giveaway that you can do this. and this is where you can actually learn a heck of a lot by doing troubleshooting like this. Because you go in and then you go.

Oh, what is this part? Like you could do a tear down. Take a part. Random things, you go. I have no idea what this is, and you can slowly use clues to figure out exactly what it is.

But anyway, it's almost certainly a mosfet. So if you have a look at the data sheet for the mosfet that I actually, um, sucked out of the dumpster laptop that I got and used as a replacement for this, then you can see down here. it's a just a regular mosfet like this. and it's got the four drain pins on one side and the three source pins on the other with the gate pin.

And that's exactly what we're seeing in this uh, photo here. So right off the bat, we've identified this as it's almost certainly a mosfet of some description. We don't know the specifications, we don't know anything, although you can kind of guess at the specifications because this is, uh, like, for example, uses a 2 cell 8 volt lithium battery for example. The rated power is 45 volts in this thing.

Anyway, if you get your confuser out, you go like 45 watts maximum power. You divide it by 8. For example, assuming it's doing some sort of you know, battery switching or driving for the Leds or something like that, or only talking about, you know, 5 amps or something like that. So you'd be looking, ballpark that, this would be at least a five amp.

Anyway, at this stage, you're guaranteed that's a mosfet. Uh, you know, it's probably maybe five amps or something like that. And you can see. like the big traces.

You know it's related to the battery. You know the batteries are delivering all the power when. uh, it's not powered. Uh, from the mains, so you know, you know.

look. and there's big fat tracers going to it. And yeah, look at the size of these traces, right? Huge, big, thick tracers. That means they're carrying a lot of current.

That means you're talking amps instead of like milliamps or hundreds of milliamps. And therefore, based on the Uh power specification for this, uh, like maximum power specification, you know you're talking like, you know, five-ish odd amps. So it's definitely not like a signal, uh, transistor like we've got down here, right? Little Sot 23 package it's called that's also a Q5. You don't know whether that's a Bjt or a mosfet could be either.

Really? Um, you just like, yeah, I wouldn't even like to guess at that. So how do we get the part number? Well, it's We don't seem to have like a date code on this thing which will be two digits and two digits. Um, in fact, do we even have a chip on here that actually has a date code, not the charger chip over here. It doesn't even have a date code.

It'll be uh, year and week basically. So if it was made in, you know 2018 for example, it would have 18 and then another two digits would be might be you know 18 again which would be the 18th week in 2018 for example that it was made. But anyway, right off with the bat, we know that second row of information. there is not a date code.

Rr6sa. Well, that doesn't sound like a part number to me. And if you're familiar with mosfets. and once again, if you I just go into your digikey mouser funnels and 14 who, whoever it is, go in and search the parametric table for mosfets and you'll get familiar.

That yeah, a 4303 sounds like a you know, kind of a familiar-ish kind of number. So I'm going to run with 4303 is the number of the mosfet. And up here we've got 4307 and this has got Rt26s. So these are like radically different.

So that second line of information there that doesn't seem related to the part number, right? So the first thing I do is I will search for 4303 Pdf. Let's see what we get. It's not national instruments, all data sheets. Okay, nothing is generic coming up.

so Gw instead. Um, no, right. Oh, Analogue.com Ltc 4303 a hot swappable two-wire bus buffer. Well, no, it's not that we know it's a Mosfet.

So I would search for Mosfet and then Pdf. I like adding Pdf to the end because it gives you a data sheet link. Pretty much off the bat. Well here we go: Sm 4303 Mosfet so we can go in.

I'll right click on that. Pn 4303. There you go. That's a Jfet, right? That's a junction fit.

Jfets are not power devices like this. So yeah, I don't think it's a 43. Oh three. Here it is.

Sm 4303 Pdf data sheet. There you go. We got it. Now this is interesting down here on Semi.

They're a big manufacturer so you can see that I've clicked on that before when I was, uh doing my searches. Let's have a look at the on Semi. What's on Semi got for the Ncp 4303? Come on interwebs. Aha, this is not a Mosfet.

Are we wrong in our analysis of the Pcb? This is a secondary size synchronous rectification driver for higher efficiency switch-away power supplies in a Led lamp. Uh, like that Led light like this? You'd certainly expect a bunch of uh, switch mode power supplies. In fact, there's inductors and and other things in there that show you this has switch mode power supply. So were we wrong? First thing is, just take a look at the pin out and you can see that Well, no, you wouldn't short out like pins one, two, and three here and you certainly wouldn't short out eight, five, six seven, and eight on this side.

So you know it's a mosfet. So there you go. you can be let up the garden path there. It just happens to be the, um, the same, uh, part number 4303 and the other links we got were like starter Mosfet 4303 Mosfet.

Boom. It's a P Channel mosfet for maximum power dissipation 4.30 volts. That's what we're looking at. Okay, and with another link here.

but bingo. We did eventually get a link over here to Datasheetspdf.com and sure enough, uh, we do have a data sheet down here. A Sino Power. Um, data sheet.

I had never heard of Sino Power before, but Sm 4303, Psu. So there you go. Click on that and unfortunately, that is not the correct package. So um, yeah, you might stop there.

But anyway, I'm going to have a look at Cyanopower. Another thing we can do is go to your favorite catalog suppliers and we can go 4303 like this and it'll give you a bunch of links like that. but I don't want to click on those. I just want give me everything Transistors, Mosfet single.

There we go. There we go. Let's have a look down here. Um, that is not the number.

That is not the these are not the droids that we're looking for. Um, yeah, nah. Um, something's wrong there. so I'm not sure is where was that in the part? Maybe that has it obscurely in the part number somewhere.

I don't know why that's a match, but anyway, that's all we got right on digikey. So obviously this 4303. We know it's a mosfet, but it's not a mainstream part number mosfet. So what we do now is search out for that Sino Power which we got before and maybe we'll get lucky.

And sure enough, here's the website: Sinopower.com We have to. let's go to the English version just to help us out a tad. Look, we can go in. Stakeholder Engagement Fact sheet.

Do we want to look at the stakeholder engagement? Anyway, this is it. Turns out it's a Taiwanese manufacturer and it looks like they specialize in just this is their main product page. Nmos and Pmos. Um, the Pnn channel Mosfets.

That's all they do. So yeah, okay, 4303, right. You feel unlucky. We're starting to narrow this down.

Bingo Sm4303 Aha, Sop8 sop 8 package so 8.. look at this data sheet, package, tape, and real quality reports. Fantastic! I'm liking this uh website so no power and Bingo we have it. Um, the Sino Power Sm 4303 Psk and one like it's got the standard pin out for mosfets, the four pins for the drain, the three pins for the source, and the one for the gate down there which is pin four.

And that's exactly what we see there now. Interestingly, this actually has built-in gate protection you can see here and uh, it tells you over here, Esd protection and 8 kilovolts and it's reliable and rugged. Well, if it's reliable and rugged. why did it fail in our product? Anyway, let's not go there.

Um, win a winner chicken dinner. We have found the data sheet for this and you'll notice that their symbol there matches our symbol over here. so you've got to turn your head that way. and um, yeah, it looks like they match.

So this is a Signer Power brand. We have the exact data sheet for this mosfet and it looks like this part number for this mosfet is specific to Sino Power. I could not find a reference to any other manufacturer that makes a 4303 P channel mosfet like this. So it's just a cynopower thing.

So it looks like, uh, Aperture who, uh, designed these things that they actually specified in in a lot of parts in here. Look at the cyanopower. Cyanopower. Cyanopower.

In fact, all the mosfets in here, I believe are cyanopower. There's like eight or nine mosfets in here down here. down here. Two up here, one two three, four five six seven.

Yeah, it's like you know, 10 or 11 of them or something like that mosfets. And they're all cytopower. But curiously, they do actually use a different one here, which is a 4307. you might think.

Ah, okay, this is a P channel. This is an N Channel one. Well, 4307. It's also a P Channel one here, and I mentioned this in the previous video.

It's near identical, but it doesn't have the internal gate protection. So while you're designing one with gate protection, one without. yeah, I, I don't know. Um.

Anyway, I would actually consolidate these parts and as you saw in my repair video, you don't really have to match the specifications that closely for this, but we're going to assume in this particular case that we do. So how do we find an equivalent part for this? I've already said that we can't actually find this um in from different manufacturers, so I won't waste your time like going into Digikey and Mouser or Element14 or any of those I like. We can't find this anywhere. In fact, you Google it and you can't find it if we just google Sm4303.

Mosfet. Um, like it's throwing up Mouser, but these are just, uh, generic ads. These aren't matches, These aren't recommended, it's just that. um, digikey, Element14 and Mouser.

They have all paid to be in the search results when you search for mosfet. In fact, if we search for Mosfet, will these ads come up? Uh, well. no. We get the Wikipedia.

We get the guide. It's more generic, but yeah, it seems more generic now. But anyway, Look, if we do one two three four five Mosfet, right? What do we get Like we just get like diodes and carbon like Digikey Again, Element 14. they've paid right.

There is no one two three four Five Mosfet. or is there don't think so. High voltage Super Junction mosfet. Full in-depth analysis? What? No, that's a market overview thing.

Anyway, let's not go there. so there's a little tip. Don't fall for uh, these ads that you know thinking oh, this must be an equivalent Maybe you know Element14 have determined that this is an equivalent part. No, it's not.

You can tell A for the package, uh B this is an N Channel. Uh, a high voltage job 300 volts thank you very much. Um, and yeah, no, these aren't equivalent. these are just paid ads.

But yeah. so the only stuff we get is the Sm 4303 from the data sheets. and if you go and look at them all, uh, there's a there's a Japanese one. Oh, custom power design is that maybe someone makes an equivalent, But yeah, like all trend, like it's this is like oh well, we start getting into Russian stuff down here, right? Only four.

but like it's there are obviously no, uh, you know, main brand manufacturers or even equivalent ones of the 4303. Um, yeah, no. Look a rollerball quick connect? No, okay, we're just completely off track. so it looks like Cyanopower are the only ones who make the 4303.

So even though these weren't showing up and did you keep Mouser or Google or anything like that as an equivalent manufacturer, let's see if we can get an exact replacement. Uh, my go-to place would be Lcsc. They're kind of like the Digikey mouse equivalent like in China and you've seen me, uh, use them before. I've gotten like, you know, the what is it the two cent micro controller from there or something like that.

So anyway, let's go into Lcsc and uh, let's go. They've got like huge inventory. Very. uh, Digikey? like So 4303 and if we search for that, let's have a look.

Operational amplifier, fuses, compressor layer Pro Order Note: Show more results. No transistors. Mosfets Two. Bingo.

We have it. Look at this. We got one. Hey, the Sino Power look.

They actually stock Cyano Power Semiconductors. And wouldn't you know they've got eight 19 in stock. Um, and it's the exact part. And if you go in there and see the data sheet, it's the exact part.

Bingo! So we actually found this in stock, right? So we can Actually, if you wanted the exact replacement, we can actually get it from Lcsc. I think that's amazing, but it's also bought up which didn't we didn't find in google searches. It looks like somebody else does make this and I just noticed this. Now look at this.

Vbsemi So 8 Mosfet. Let's go in and see if it's an equivalent mosfet. Uh, it's a it's a P channel. 30 volts.

There you go. So once again, another Taiwanese manufacturer Vb semi that another one I've never heard of, but I just found this Now I didn't. This didn't come up in my searches before when I was doing it for my previous video. and it's yeah, it's the same.

I think it's 12 amps. Is it at Vgs? 4.5 30 continuous drain current at -10 of 14 amps at 70 degrees at 10 volts? Yeah, 13.5 So yeah. Um, it looks like yeah, there is one other manufacturer equivalent of that part. Um, so yeah.

If you're designing this product and you really, you really wanted to use this Cyto Power part because it's ultra cheap, you would also, probably um, test and spec in this Vb semi one as well, just in case you couldn't get one or the other. You might be able to substitute these And you know you'd have to go into all the details. And you know. But for some application like this, you know, as we saw in my repair video, just a generic mosfet pulled out of a laptop did the job just fine, right? So let's say that you couldn't get either of these.

Let's say they didn't have stock or you couldn't get them or whatever, right? You're you're stuck. How do you find a replacement? Well, this is when you have to go into the data sheet and you have to look at the specifications. Well, for mosfets, what specifications are the most important? Well, it's got to be Ap Channel. Okay, it's got to be either a P channel or an or an N channel.

So you definitely want the same. You want a P channel, right? So right off the bat, that's your main selection criteria. Uh, then you need it needs to be an enhancement mode. Uh, mosfet.

Um, they're like most generic mosfets are enhancement uh, mode mosfets so you know you don't really have to. That's not something that you'd search for generally. Um, that's something that just like comes out in the wash. But the main requirements are for the mosfet are your voltage and current uh requirements and the power dissipation for the part as well.

But we'll you know we'll have a look at that. Okay, it's nominally 30 volt rated. They they put minus in there because it's a P channel. If it was an N channel, that's how you can tell.

even some data sheets don't tell you if it's P channel or N channel. Here's how you tell it'll be. If it's P channel, it's minus x volts. Or if it's N channel, it's going to be positive.

So it's a nominal 30 volt, 17, 17, and a half amp mosfet. But as we did the calculation before, this thing's only going to do like five amps, absolute tops, or something like that, so you know it's being used. Uh, it's way over overspecified for this application, which is very common. Of course, that's why I didn't have any hesitation in using this alpha and Omega one that I pulled from a laptop.

Um, as a replacement. it's a minus. It's a 30 volt 12 amp one instead of a 17 amp one, but it doesn't really matter anyway. The third thing we have to look at is the Rds on At and that will be given at a particular Vgs or gate source voltage.

Um, and this particular case, they usually give you like two values and these are fairly common. Uh, like 10 volts and four and a half volts Or five volts or something like that. So Rds on is the Rds means the resistance between the drain and the source pin because this is the transistor and the gate actually controls it. So it's the resistance uh, between the two pins when you enable the mosfet because in this particular case it's just being used as a switch, basically off or on.

Um, so it's going to be completely open or it's going to be completely shorted. and the when it's completely shorted, it will have an Rds on. That means it's switched on of 9 milliohms maximum. Uh, and but that's at 10 volts.

If you've only got a 5 volt drive, say you've got five volt circuitry actually driving this thing, then um, typically then you're going to get, you know, 15 milliohms something like that. So these things so you want to have at least those uh, specifications to match unless you're certain. Like I was that this was a well over specified component and the Rds on it didn't really matter because I knew that this particular part. it doesn't get hot.

These so-8 packages. These have no thermal pad on the bottom so they're not dissipating any uh, power? Really? You know this package I think is what was it rated for? four watts or something like that. If your S08 package is dissipating four watts, Oh, you're gonna be getting the heebie-jeebies. Um, it's going to get like super hot.

So yeah. Anyway, so I knew it was used well under specification. just based on the top level product spec for this lead light that I've got. There's just no way it could be using it, either charging it or are consuming the current to power lights.

at anywhere close to its 17 amp rating, it would be a five like absolute tops. So that's why we had nine milliamps and 15 milliohms here. That's why I was safe in using a Uh one that had 14 milliohms and 30 milliamps. So double right at at five volts.

Here at Vgs five volts it was double the resistance. But even at 30 milliamps like 5 volts, I squared r 0.75 watts even at 5 ohms and it's going to handle that's well within like the thermal specification of the package, which you should be able to get down here. Here you go: Maximum power dissipation down here at 25 at ambient temperature of 25 degrees C 3 watts. or if it's like getting hot inside this thing as it would inside a lead.

you know, light like this with no circulating airflow or whatever to what's maximum. So even if it was being used at five amps where like, well under half of its maximum power dissipation. So yeah, I just knew this part was going to be fine and it was going to work. So for something like this application, that's I could get away with using almost anything.

And in terms of maximum voltage here: 30 volts Once again, this is over specified. We've got two battery packs in series here. absolute maximum at uh, eight point. um, whatever volts each.

so you know something. 17 18 volts is all that's required. So 30 volts was well over specified. but the replacement part was identical voltage spec.

so I had no problems there, uh, whatsoever in using this one. And sure enough, it worked because I knew, um, just basically the topology of what's going on here. Okay, here's the two battery connections here. and uh, you can see in the repair video especially.

And I did a two-hour live video as well. actually debugging this where I talked a lot more about like my uh, theory behind this as I was analyzing uh, the circuit and stuff. I mean, this was obviously doing switching of the batteries here, either uh, charging or using them as loads. So you switch them off, you switch the charge in.

um, or you can switch. or you can switch them out so that, uh, they're powering the product and stuff like that, so you know. I I knew that these things were being used as switches for this battery. So for a switch application, you can pretty much ignore like every other specification on this data sheet.

apart from voltage, current, Rds on, that's pretty much, um, all you're gonna have to do. And I wasn't worried about the fact that it didn't have internal gate protection like this. If it blew, it blew, who cares because I zapped it with these like it, it doesn't matter, right? So that's why I thought the absolute the absence of that really didn't matter are rats. So the absolute maximum are specifications.

Yeah, the voltage and the current will well within that junction temperatures doesn't matter, it's not being used in a blast furnace or something. Uh, maximum power dissipations were well under that. um, the thermal uh values as well. We're not dissipating these when in operation.

I could feel that the chips weren't even getting warm at all. Um, so yeah, it made like they weren't disciplining any power so your degree C. but what? Uh, thermal thermal resistance, junction ambient. I've done a whole thermal resistance of videos done a couple of those.

they're really good. Link them in, you know, and we don't care about like zero gate like drain current and stuff like that. Whether it's like like mike 10 one microamp or 10 microamps like, yeah, it doesn't matter, right? This is not some critical application gate threshold, uh, voltages. This is not some ultra low voltage thing, so we're not worried about anything like that.

The gate leakage current, you know, like who cares, but that Rds on. we've talked about that and they give typical values here and then maximum values over here. You might have to go into typical versus maximum if you get in a bit more like on the margin. uh, whether or not you think your part might be equivalent or not, you might you know, like typicals versus maximums might matter.

You might have to look for some parametric data further on your data sheet, but you're really getting into details now. I could do like a two hour video solid of going through every single specification on a mosfet data sheet and we don't worry about like reverse recovery times. This is not used in some ultra efficient switch mode converter where you know stuff like this is going to matter In terms of oh, that's makes the difference between whether it's a 95 efficient switching converter or whether it's a 90 efficient switching converter and stuff like that we just like it, we just don't care. And stuff like the uh gate resistance which is related to the gate capacitance at like a one one megahertz doesn't matter, Then you've got input capacitance, output capacitance, reverse transfer capacitance, all this sort of stuff.

It's only if you're dealing with, like if if you're doing a repair something like, this. like especially mosfets. Um, and in this particular application, they're going to be used for either logic switching, power switching as we've got in this case, or they're going to be used in switching converters. It's only in switching converters that you'd really start worrying about anything to do with any of these dynamic characteristics.

This is why they call them dynamic instead of static characteristics because it's dynamic. It's only when they're switching. this is not used in a switching converter, so we have no need for any of the to care about. I won't give one rat's ass about any of the dynamic characteristics and gate charge here.

Once again, this is another dynamic characteristic of how much actual charge is required to turn on the gate, and that's related to the time and everything else. And we don't need to worry about any of that. And likewise, I didn't even need to look at any of these characteristic curves because, uh, we just weren't even close to it. You know, thermal transient impedance? you know, like, and a safe operating area? No, we're just looking for.

you know, is it sort of like Jelly bean equivalent? But what happens if you did want to match this closer? Well, we would have to go over here and we would have to choose. I'll just choose Digikey because whatever you can use mouse, you can use Element 14. You can use any other parametric search engine that you like anyway. So we're going to search to try and find an equivalent like you know, a name brand part that we can get from many different manufacturers to look as a replacement.

And you might be doing this of course in your design process as well when you're finding equivalence. Okay, you found this Sino Power one and it's two cents in volume beauty. But just in case you want to have like a couple of Aquila equivalent parts on your bill of materials, just in case, you can't get that super cheap Sino-power part, or there's a war in Taiwan or something. and boom, You instantly can't get, um, you're demonetised.

You can't get your Taiwanese parts. So anyway, we go into Mosfets singles here because it's a single jobby, none of this array, rubbish, and Mosfets. And here's all the manufacturers that, uh, Digikey carry. Look, there's ones I've never.

You know this. Catalyst Semiconductor, and Alpha Omega. They might be a bit obscure to a lot of people. Central Semiconductor Corp Never heard of them.

Com Chip Technology d Components, Galco Industrial Electronics like you know, Like, who's heard of these companies, right? Unless you were doing. Unless you're looking at Mosfets a lot. which I haven't been doing lately. Um, you know there's A.

There's a few names in there that I don't recognize. Wolf Speed Inc. Zhang. Yeah, okay.

anyway. parametric searching now. Okay, P Channel is the big thing. Okay, we want apply.

All okay so we only get P Channel mosfets. And really you could say well, only active parts. Um, you don't want discontinued at Digikey? Probably you don't want last time buys. Um, that means like a manufacturer going has putting out a notice saying that we're not making this chip anymore.

If you need them, buy them. Now this is the last time we're going to let you buy them so you better buy a million of them. Otherwise, don't you know you'll be sorry. So and not not for new designs obsolete.

you don't want any of those. So we want active. So we've got 3170 right? So you'll see that we have a whole bunch of specifications here. We've got drain to source voltage, continuous drain current, drive voltage, Rds on uh, Vgs, uh Max.

We've got gate charge which is you know the the, this, and those dynamic characteristics we're talking about. Uh, Vgs Max input gate capacitance Um, Shocky Diode isolated whether or not it's got special features, it's got a shocky diet in there. Ooh, fancy pantsy. And then of course package package is the other big one.

If we can't find the same package, there's just no point. So let's go S-i-o-i-c Okay, we want the standard width. thank you very much. Okay, we don't want any of that.

uh, five millimeter width rubbish. So there's now 278 remaining. Okay, so we've dropped it way down. We can still get the one with the shocky diet in.

Are you sure you don't want it? Are you sure? And we could actually narrow that down a bit. S-o-s-o-i-c S-i-s-s But let's just leave that for now because sometimes they might actually have those sort of things incorrect. Like they might actually have the width. Uh, the width is more likely to be correct than one of the supplier device packages.

Anyway, You can you know? Just be careful. Look, Look. we've got Bgas. Why Why are we getting Bgas? Why that's not an So8? Yeah, we've really been screwed over here.

Aha. You see, if I scroll down here, they've miscategorized some of these. A Pg Dso 8 is in an 8 pin Soic thing. So you see how I warned you that the supplier device package might actually be wrong.

That is actually the case here. Um, this is a good example. So I'm going to go so. and Soic like this, apply all Sop.

Well, let's let's just try sop as well. Okay, so if we do that, Bingo! Now we've got all of our S08 packages. We have 270 devices. Well, we could go in stock, but at the moment, how many 65? Okay, we can get 65 that are actually in stock.

Should we stick with the in stock ones? Yeah, let's let's stick with the in stock ones because the in stock ones are most likely to be ones that have generic equivalents from different manufacturers. So oh, Rochester, If you see Rochester Electronics, they're actually a a obsolete component supplier who do actually like whose stock they stock, wafers, and everything else. We discuss this on the Amp hour many times. Yeah, nah, you don't want one from Rochester Electronics.

But anyway, these are more generic part numbers that I'm seeing here. These are from Fairchild Diodes, Inc. you know, Vichai, right? Infineon? Yeah, these are all your main brand ones down here. Okay, so the next main important requirement is the drain source voltage.

Like the maximum voltage of this part. Okay, don't worry about the gate source voltage. let's go for the drain source voltage V V D S S because that is what we'll find here. Drain to source voltage.

Okay, it's so important that it's over on this side of the Uh of the parametric table. Okay, so we're looking for at least 30 volts. Okay, you'd want to match it. Um, in fact, I wouldn't go as high as somewhere you could.

Okay, if we put that 65, that's narrowed it down to 40.. if we narrow it down to like exact equivalent, you can see up here it's 34 remaining. Okay, so let's actually go for an exact 30 volt equivalent part, right? So let's go apply. All okay, we've got our 30 volts like this.

You can do this like multiple times. You don't have to do it one by one. But anyway, now we're left with our continuous drain current. So what we we looking at here? We were looking at 17 and a half amps because that's going to be the banner spec at 25 degrees C.

They're a bit naughty there. They'll just give it to you at you know, ambient temperature. Whereas inside your product like this Led light, it's going to be operating at a higher temperature. But that will be the banner spec, right? 17.6 amps.

Okay, so that's what we're going to find. You're going to find the banner specs on the data sheet here. Okay, so we're looking at least could be that one. that's 19.3 amps.

I'll include that, but like we're looking at 18 22 amps, 34 amps in a S08 package. That could be special. Anyway, now we're narrowing it down, so let's apply. We've only got six remaining.

Okay, that's not many. so at this point we might actually start regretting. Um, choosing the uh, like, like in stock option or whatever. Um, so yeah, stocking options.

We could actually take that back out if we wanted to. But anyway, these are the ones we've got here. Okay. Vichai Siliconics? Okay, so they're You know they're They're absolutely huge.

So that's 14 amps. I don't know why it's like a jewel anyway. Um, these are getting pretty pricey. Aren't they 75 cents? You know, 2.13 2 bucks.

50 right? from Rome. Anyway, we've got a good. we've got three manufacturers. At least we've got Vichai, Uh, Taiwan Semiconductor, Um Corp? Well, you don't want another one from Taiwan.

You remember that War thing I told you about. So you might you know you might go with uh, Rome or somebody like that. Okay, anyway, the Um. Si 4153 sounds like a much more generic-y type mosfet number.

I don't know. I've never used. it. just sounds more generic-y than a Tsm-05085p03 or an Rse3 Rs3e 180, right? So so I'm going.

Oh, there's no data sheet. Ah well. screw that. they can't even give us the data sheet.

Okay, there's another vacher one down here. 44.25 Let's go for that, Joby, Shall we get 645 of those in stock? Now you notice. Uh, one thing is that this thing doesn't have what this one has, which is the gate protection down here. So if you wanted something really equivalent, did we even see that feature on the digikey? I don't think we ever saw that on the special feature.

You'd have to go right back to the beginning. Most fit. Don't search for most fets. Um, search for mosfets.

Highly recommended singles. Okay, we'd have to go back into here. then we'd have to go across. Maybe you might get it as a Fet feature.

Current sense in depletion mode Logic level Gate Shocky Diode Body Isolated Standard Super Junction I'm not getting any thing there as a special feature. Um, for internal Esd protection, right? So you might have to search for Esd protected P channel mosfet or something. Getting desperate Now Esd Protected P Channel Mosfet s08. We're using Google as our parametric search.

Okay, we're getting a bit desperate now. Esd Protection Up to Eight Eight kilovolts. There you go it. It may not show it actually.

Um, oh yeah. we've got a uh, I've got a promotional blurb here. so 8 equivalent and that's exactly what the application we've got here actually. Look at this power source, the batteries, the load circuit.

Oh yeah. Esd protection. Battery Battery application driven features. Esd protection because you want that because when you disconnect the batteries, right? Um, the contacts are often exposed to the user and they can zap those.

So you know that's probably why they've used the Esd here. But they've also got another part there that's even closer to the battery terminals that's not Esd protected. So, but yeah, you've got to go to like this specific Sia 46, 4, 6, 7 Saa 4 6. Anyway, let's let's have a look at that part.

It's only a 12 volt mosfet. Okay, so we didn't have the equivalent there. but yep, they are that. This one interestingly has the uh.

protection between. uh, drain? Oh no, they've flipped it the other way. Okay, they've put source at the top, whereas here, they've put our source at the bottom like this. so it's gate and source.

Okay, so yeah, all the electrons going to fall out of that one. So yeah, um, technically we can't use Digikey to find a direct equivalent part because we need that Esd protection. I mean, if we weren't, if we ignored the Esd part of it, then well, you know we could get almost anything. So we could actually just probably use this.

uh, 4425 here. Um, it's you know, like I could look. I could spend an hour going through. like the characteristic curves and everything.

And and the Vgs at 10 volts. Anyway, you'd start. You know, comparing your on resistances for a step maximum of 12 maximum 21. Uh, that's 21 milli ohms that is they specified in Ohms.

but uh, that's 21 million so I think that's under the other one. So as long as you had them under and stuff like that, you're probably good to go for a switch for a static, uh like switch and not switching but a uh, like a switch application. Um, whereas in, you might have to get more into your dynamics uh, switching dynamics down here. especially if you're in into the design side of switch mode.

uh, power converters. You have to be really careful, do extensive testing and stuff like that, um to get equivalent parts for your bill of materials. But for something like this, we could probably get away with this part here. But anyway, we have not found.

This is like we we can't search for an Esd part like this on digi-key I mean you got to remember even this. Like like equivalent part over here that had 4303 in the title is a very different mosfet. It does not have the Esd protection built in. it's it's very different so that if that was key to your product and you put accidentally specified this one in thinking oh yeah, no worries, it's got to be equivalent.

You looked at the top level specifications and looked at the part number 4303. It's got to be the same right? I'll just whack that in my bill of materials and then you couldn't buy your Sino Power one and you went to make a hundred thousand of your farting novelty gadget widgets with your Um Apm 4303 and you find that well, five percent of them come back as far in the field because you know, Little Johnny's been zapping the Uh terminals when they take the batteries in and out so you can come a guts up completely that way. So yeah, um, just because it's got the number in the part number, the exact number doesn't mean it's equivalent. It's not.

It says no Esd protection. So this 4303 is looking like a bit of a special snowflake. really. Um, so anyway, let's let's go over to Mauser and see, let's be the United States of America, shall we? I'm going to choose P Channel.

Look at this. Look. Look at this. N Channel Snobbery here.

They only get one option and then you can just go generic Smd. But because we know exactly what package we want, right? like we, we may not find an equivalent. I like odds are we probably won't find a direct equivalent with Esd protection built in. In fact.

Um, let's before we even go to that. let's see if. Nope. Mouser don't even give you any options for like they've just got trade names.

Um, like which isn't going to help? Um, there's no like Esd things at all. There's nothing. There's nothing no like special features. At least on digi-key you've got like special features.

Okay, let's do moose fets in Element 14, shall we? No, we don't want transistors. See they have different. they're they're discriminatory. They have transistors and they have fets.

Come on, we want our single mosfets because uh yep, you want to have a good time. So you want a single mosfet and if we search down here oh I don't like the way they do it here in these the boxes. oh it's just new. Yeah on resistance.

K-star transistor mounting Rds power dissipation number of pins operating max product range. once again, they don't we. We're getting nothing here. Nothing on the parametric search for like to be able to search for an internal Esd part.

So like this is a special snowflake we've picked here. Finding an equivalent for this is it might be impossible getting dead. Most I did most fit. Again Rs components have 10 000 most fits.

I think I'll call them. Most vets from now on. Why not? Anyway, here we go. This is a bit more sensible.

brand channel type transistor configuration. Number of elements per chip like yeah, nah, I'm not seeing any. Like any ability to be able to search for like unless you're like you might get one like you might have to like search for a whole bunch just randomly until you found one that happened to have Esd protection built in. Um, I just I don't know.

You might have to go to the manufacturer's website parametric search and now we're getting pretty specific V Shall we Mosfet? See, we could, uh, try and cross reference a part number. Maybe like Sm 4303 but like, as if Vichai care about like some obscure part from Sino Power. I'm doubting it. Yeah, Zero.

All right. here we go. I didn't I shouldn't have searched for the keyword. I should have gone into the products down here and we get our parametric table.

So Dual plus Integrated shot key? Uh, no, it's not an integrated shot key. No, they're just all your values. So it's it's not the integrated shot key, right? Let's have a look down here. that's just a very different thing that's like literally an integrated shocky diode.

Like a reverse shot key across there instead of like all mosfets will have. Um, the regular, um, like reverse diode in here because it's not actually a physical diode in there. It's actually just an inherently in in fact, a lot of cases unwanted part of the physical way that the mosfet is constructed on the silicon. It just gives you a reverse bulk.

It's often called a bulk diode or a bulk junction diode because it's part of the bulk silicon in there. but this one actually specifically has engineered in there. Another, it's got the irregular bulk one because it's integrated in there. But yeah, this one's super special in that it has a shocky diode on there for switching applications with monolithic Schottky diode, right? So this is designed for like really high efficiency switching applications and stuff like that.

So yeah, there's just no parameters there to search from so we'd have to go through and search for Esd protected mosfet. in fact. Yeah, as like we're almost better going back to that Google search so we can search for on semi look. I just searched for Esd Protector P Channel most fit and yeah, let's search for here we go right? So maybe if we search for most fits in here will get something that has internal mosfet protection.

Maybe we'll get like a a parametric box which can tick compliance. Uh, no, that'll be like Ros compliance and stuff. Channel polarity configuration. What's what's configuration? No with shot keys? No.

so it doesn't have that parametric uh search option but obviously like it's in the title. So I search for P channel Esd protected and sure enough I do actually get a few of them. but you know, minus 12 volts. Okay, not suitable 12 volts.

So that's obviously an N channel because that's positive. No, it says P channel, but it says 12 volts. Okay, but it's in an Sc 88 package, right? So uh yeah, that's another Sc 88 that's a dual one that's obviously not suitable. Power Single channel? Uh.

12 volts. Once again, Sc uh package only three amp. Joby? Like, uh. 20 volts.

Okay, so we're getting up there. but once again, that's a dual, so no good. Um, and another jewel here. Ah, we're almost to get in there with this one here, but this is A.

I don't know it might have another package in here, but no it doesn't so you can forget that. Um, you're getting pretty desperate, but technically it does have a thousand pages here, but I think you're gonna get diminishing returns at this point. I don't think we're actually going to get um, yeah, the the 30 volt jobby. I mean, I can put -30 in there and we get ones down here, which are actually an So8 package, right? But if if you go over there, it does not actually have anything to do with Esd.

So we've already gone away from actually getting an exact um search term here. So so maybe you know you're getting pretty desperate now from the mainstream manufacturers. Unless you checked every mainstream manufacturer website, you see how hard this is getting. I mean, we can go back to Lcsc here, right? But even Lcsc right does not have um, like any Esd even in the search description.

so we can't do that. I mean, we can go to actual, uh, Mosfets. We can go right back to searching like and then all of these like more obscure Asian brand which we can get from Lcsc. I mean, just check out all these you've never heard of, right? Ninety percent of them? You probably can't What's California Eastern Laboratories? Um, anyway, right.

and you know there's a few in there that you recognize, but most of these you aren't going to recognize. Okay, so there's a whole bunch in here, but unfortunately, there's no parametric search in here with I mean, there's a type. Maybe you'll get, you know. No, it's just like a P channel.

So like there's no parametric thing in here to search for Esd. I mean we can search for Mosfet. Esd. Let's see if we get lucky mosfets for that mentioned Esd.

Whoa. Hang on, Is that Sino Power again? Esd. There you go. It's got Esd in the number that's like in the actual manufacturer part number.

That's interesting. that's worth checking out, but that's a T stop eight. Um, geez, we can't win, can we? No, no, but let's let's check that one out anyway because that's interesting. Oh nice.

see that's a jewel jobby. Okay, but uh yeah and that does have gate protection. So we found it. like um, is there a single no? that's not.

They're all jewels. The other single seems to be down here. Oh, that's like an old school J Fetty number. Um, 2n 7 000.

So an end channel mosfet with gate protection in here? but still? Um, yeah. Okay, great. We found another one. Um, but it's not an equivalent part.

Not by any stretch. it's only 300 milliamps. It's not a power part. This is not a power package.

Um, it's just a 23 jobby. And yeah, you see, like this, this may actually be impossible. Okay, I'm getting pretty desperate now. P Channel Mosfet So8 plus Esd.

Okay, and I got this interesting infineon uh selection guide here and if you check this out right here we go. look. ah, they look happy. Look at that.

They're found, they're founded. They've found their P Channel 30 volt So 8 mosfet with Esd protection built in. Oh fantastic. Anyway, this is.

this is pretty cool, but if we search for Esd right? look it's it's popping up here in the sop 23s. Okay, you can see that tacked onto the end of this is Esd uh, Esd protection. But we obviously we want the S08 damn it, right? So we have to go down here and we have to go est esd. Uh yeah, no.

Go to the next page. Nope. It jumps down right to the bottom. So there's no Esd in an S08 package.

but you can see that Infineon actually have in their part number. You can have actually have an E in the configuration which has Esd. Um, there you go and you can get ones with integrated gate resistors and fast switching and qualified for. you know, certain standards and stuff like that.

Um, but there you go. No Infineon S08. Look at this. you know, seems fairly common.

Like these are all -30 volts, right? So there's a big selection at that 30 volt window, right? They're very common parts. Um, but you know, like we'd have to get into the 17 amp plus down here. Oh no, I thought that was amps. No, that's going to be Rds on, right? No, that's going to be Rds on.

So you want the like the lower ones down here. So these parts but they don't have and well, what's that? Does that have an E? Does that technically have an E in it? Um, I I don't know. we'd have to. You have to search for that.

Can you get it with and without? Um, do we get the data sheet? Here we go. Oh we can get 2 2 400 in stock. Wow. um yeah like it doesn't show it.

Um F Esd esd class it? Just no, no no no, nothing doing. I come on and we could do this. Like for every manufacturer, you know how many manufacturers there are including all those Asian ones. Um, come on.

And then that search. look a bit further. that turns up this Nxp. um like application? Um thing.

Uh, like Power mosfet application stuff. Um, see, they don't have happy people who found their they've just got a dodgy old uh, Quadcopter in there looks like the one I built. Um, and you know you search for Esd and it's kind of like in there like you can get like some have Esds but that's like kind of like it. Do they have Esd clamp protection? Do they not? I'd like.

You know. Nah. Sort of. Yeah, Well, let's go back to Digikey and let's just see if we can get lucky.

Let's Esd. Mosfet transistors, fets, mosfet arrays. No. so we only get a raise.

Okay, yes, because they're Esd protected arrays. They're designed for protecting Esd protection on like, uh, logic, lines and stuff like that. No, no, No. So yeah, that's that's a fail.

But I'm I'm just desperate to find anything that's Esd protected. and I'm I. It's not going to show up in the description like you would have to get desperate and maybe go into each one and you might get lucky. I mean, you know, just like randomly open them.

That's what you get when you get to Rochester Electronics. As I said, um, yeah, obsolete stuff. They specialize in that. Great if you're into military stuff and you're trying to find a 20 year old part or something to fix your tank.

but you know? look Anyway, Um, yeah, like there's nothing here and sometimes you'd have to be careful. They may not actually show it in the equivalent circuit, but it might actually, you know, tell you that it's like Esd. uh, you know, compliant or whatever. But I'm I'm having a hard time.

Yeah, this is getting this is getting ridiculous, right? So yeah, I think that's Cyanopower One. It's pretty. It's very special. Snowflakey.

Um, like. I'm sure like we can absolutely get another mosfet with Esd protection, but trying to get it in the same package Uh, trying to get it in the same voltage and current and Rds ratings is is another thing entirely, right? So I just think we're out of luck. so I'm I'm going to call it quits. I like I.

When I started this video, I didn't um, think oh yeah, we should actually specifically search for the Esd one and we can't really? So once again, this video could be twice this length if I went into specifically searching for all of the parameters. Um, you know, like a matching part down here. But like we can't even find a simple generic match for this one that has the Esd protection built in. Even though we go to, we can find one manufacturer with the exact, almost the exact same part number.

except it's got their own, you know, prefix on there. but it's a 4303 and that's then that doesn't have your built-in protection. So all hail the Special Snowflake Sono Power Sm 4303. Psk.

Um yeah I I don't know. Leave it in the comments down below. Maybe I'll have a more squiz, but if you can find it's a challenge. If you can find a matching uh part in the same package with the same voltage and current and Rds ratings, I will give it that and Esd protection on the gate.

Leave it in the comments down below and you can win the Internet. So anyway, I hope you found that useful. Just you know, showing you like different methods to actually search for stuff and um, it's I highly recommend. Like taking stuff apart and just trying to figure out.

You know if a newbie takes stuff right? it's obvious to an experienced person that you know these are going to be mosfets and things like that. But you know, start taking stuff apart and see if you can identify what things are. In fact, that could be a good video. Like you know, just random tear down stuff and go right.

what does that part do? Okay, let's try to figure out the circuit configuration around it and the package and the traces and the reference designators and we'll try and you know, figure out what that part's actually used for. That could be interesting. Anyway, I hope you found that video useful. If you did, please give it a big thumbs up and discuss down below.

Catch you next time you.