 Every single week we do the great search brought to you by digikey. Thank you digikey for helping us do this show and so much more We got a question on one of our last Great searches from Aaron. We know everyone about girl and Aaron says What would you recommend for part selection when it has less than a hundred stock? How can you tell if the part is being discontinued or just waiting more to come in really like the series find a super valuable to Learn these tips and tricks keep it up We need a okay answer We're gonna cover that today because Coincidentally, maybe the part that I'm going to be searching for isn't in stock And so let's see how to well first off. We'll find some alternatives But we'll also see to figure out is this part ever coming back in stock You know, you don't always know right sometimes parts are discontinued I'll give you some some tips and also how to tell when it's gonna come back in stock Used to be a little easier find out did you keep but you could still find that information if you're sneaky So let's do this thing Okay, so we're going to get a can bus transceiver for the sam e 51 featherboard that I've designed The sam e 51 is a three point three volt microcontroller can bus is really ancient It's like midi ish. It's like this very old simple, but very popular and effective Industrial protocol for sending and receiving messages. There's like extended versions. There's like high speed versions. What not? But basically it uses a five volt differential signals I'm still not 100% sure why sometimes you can get away with three volt differential signals But it seems like everybody kind of wants especially if you're doing automotive you really want to do Plus or minus five volts That said your right controller is gonna be three volts So it's one of those like three volt data, but then out here. It's five volt data So you want a chip that can kind of handle both, you know, like peanut butter and jelly go great together Three of all one side five volt on the other keep them safe, but also have that nice big differential voltage so you can Was sending received messages even in very noisy situations like in a car so the first thing I do when I want to spec a part that goes with another part is I actually look at the eval board because The eval board now first off your it's not unusual the eval board is going to use parts that are from that company So it's not necessarily always the best part, but it's at least a part that you know is going to work So in this case you go to your microchip site They have for this chip the same E 54 explained pro the same E 54 is like even better than the same E 51 But yes ethernet, but basically it's the same chip just has this extra peripheral and in documents you can download the user guide which I did and The one of the most frustrating things that can is like searching for the word can is very difficult because the word can is used in English a lot however You get eventually to this section where they talk about it and they say okay It's connected to an ATA 65 61 physical layer transceiver That's the thing that converts the you know RX and TX three-volt signal to the plus or minus five volts like it's like Dominant recessive or something. There's some wording that they use So this is their chip. So again not too surprising This interface controller is From the same company that's that's not a bad thing. I mean, I'm not against it I sometimes mix and match in a design, but there's nothing wrong with also just going with the supplier themselves and then in These documents you can look at the data sheet high speed can transceiver communication speed up to five megabits per second one thing that you'll want to Oh, I don't think I have the Sam E 51 data sheet open Hold on I've got but the Sam E 51 data sheet implies that the Canvas controller is it can do like a one megabit per second or it can do up to 10 megabit per second So it's I think you can do quite high speeds So that's something. Oh Yeah, wait, so this is the This is a day sheet. I did have it open Yes, if you find the can bus controller it can do can fd which If you like search through 2000 pages, it does say somewhere like oh, it can do up to like 10 megabit and This transceiver can do up to five megabit So that means it's just like okay If you're if you're gonna find an equivalent one you'll want to have it about that speed capability The other thing that you'll see is basically the voltage So the the protective voltage input like how much voltage it can handle before failure It's usually like 60 to 70 volts depending on your You know industrial requirements that might be important to you there's two package types these tend to come in SOIC and There's two very similar, but not quite the same Pinouts, so you'll notice that they have TX and Ground and VCC and RX and then stand by can H. Cannell and then this one has like Not used. I don't know what and sale is and this has via. Oh Via. Oh is on this sixty five sixty one and that is the version That can handle Three to five volts Logic, so that's what you want. We want the one. That's the sixty five sixty one So you have to be careful sometimes part numbers. They're shared in the same data sheet, but that doesn't mean they're equivalent This one in particular. We definitely only want the ATA sixty five sixty one, so Knowing that let's go back did you key? Don't forget to sign up and get some ESP 32 S2 chips the FR-01 and the FH chip that just came out and then in transceivers We can see Yay, there's transceivers. There's the ATA sixty five sixty one. That's what we wanted. However Some bad news this version the DFN the small chip version is in stock you can see by mousing over it's got little it's like teeny doesn't have the pin sticking out and My design is kind of already done and it's for SOIC So let's go go here. Okay. Well, you know, we can look for an equivalent Maybe I'll show an equivalent how to do that really quickly, but you'll see there's zero in stock and like You know, I'm impatient especially here's another thing to watch out for you See this the manufacturer lead time 30 weeks now right now at this moment in time Every manufacturer is having like totally nutty lead times because all over Asia There's like lockdowns and my factories aren't open and like things are very like difficult to do Do due to like government restrictions for COVID-19? however Just because it says that that's like the worst case if you said I need a billion chips How long will it take you? They're like, well, we'll get to you in 30 weeks That doesn't mean it's gonna take 30 weeks for it to be in stock. So like watch out for that. It's it's the max The min max, right? It's like the worst case So here's what we do now It used to be visible here and it's not but what you can do is you can put like a thousand or a hundred in stock You add your cart and I already had I already had some in cart so it can Change just 100 and then you see here oops Sorry, I do look it it says here It's a back order and then there's this little thing here that says checkly time. That's the sneaky thing So click that and it will tell you When they're expected to be in so they're expected to be in stock around The end of the year now, that's also very It's often quite true. I found that the lead times are a good guideline Unless there's some like catastrophe that occurs if they say that they're gonna have a shipment to digikey on 1231 they're probably gonna get it to them at around 1231 so I wouldn't like Bet my manufacturing line on it like if I absolutely needed to have it You know the next day I wouldn't Trust this because you know it can vary there can be shipping delays or can be a storm However, you know, it just means like will is ever be in stock again. Yes in a couple weeks So that's a good thing for me to know if I'm thinking about using this in my design When I can get more so I actually use that tool all the time Like I'll put stuff in stock that isn't in stock into my cart just to get an idea of like How long does it take for this to get back into stock? So I'm not so I can like kind of plan out my manufacturing runs like if I have a sensor I want to get and It's out of stock because it's everyone bought it up one of the one of they're gonna be more I can do that and I can say like oh, you know I don't have to rush my PCB design because I'm not gonna be in stock until at least, you know late December for example So that's said don't forget if you want to get an equivalent part you can always go down to the product attributes and then Click the things that you want to match up and you know, don't be too picky, but be specific enough that you can Get the item you want so you want to be an active Can transceiver with one rx and one tx. We want that same pinout The voltage supply and temperature. I'm not gonna click for reasons. However, I do want it to be the same package and Then there's only 40 remaining similar. So that's actually kind of nice. It means I can Pick out which ones now that AT 6561 was 5 megabit per second So I might want to select that and then the voltage supplies again Those are don't don't believe those Because again, there's the the voltage supply of the can transceiver, which is about five volts And then there's the reference voltage that you'll use for sending data back and forth and then So you will have to look at the data sheet and then I want the ones only that are in stock and Then it looks like there's a couple options I can get from maybe the TJ 1044 I can also be Less picky about some of these things like if I want to For example instead of protocol I'll tell you why there's Ken. There's Ken. Oh interesting. They selected multiple. There's Ken and there's Ken bus, which like I wish they would be merged together, but they're actually two separate categories for the same thing and Then I can you know sort by price or I can sort down by stock to see which ones have the most Stocks there's like a lot of of like these transceivers that the TJ or Whatever 1050 ones those are basically equivalent and that's actually ended up what I used on my design one thing that I Have started to do I prefer not to buy from marketplace. I want stuff to come directly to me from digikey And Rochester it ships from digikey So if you want it to ship at the digikey speed like the way I don't I'm picky about that You can unclick the marketplace products and then you know like this Transceiver is a high-speed transceiver. This one's from nxp instead You know obviously microchip wouldn't use this on their dev board because we're gonna use microchip however, when you go down to the specifications and The pinout You'll see it's like exactly the same So this pinout is what is this exactly same? Yeah, TX TX ground VCC RX TX ground VCC RX And then stand by Stand by high low VIO stand by high low VIO so you can you can use this basically as an equivalent drop-in replacement There's a lot of transceivers To pick the one that has basically the the safety margins you need But you know what I'll probably do is come with a list of a good three or four of these that are equivalent And that way as I'm going to manufacture if one is out of stock like that AT You know a TA series I can always sub in a TGA 1051 instead very wise always tell people when they're designing to have multiple sources for chips I have seen many companies Not bankrupt but get very close because they are waiting for a chip that they couldn't get and they were out of stock for months and months And months you don't want that to happen to you I'm making kill you because if you don't if you have all but one part to manufacture you have nothing That's my wisdom for the day. Oh, we make sure you have a backup plan for parts. All right, and that's our this week's research. Yes