List of equivalent SMD packages? - Page 1
Forum section: electronics / general

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: December 18, 2022, 10:34:41 am
content: Good morning everyone,while talking to our beloved T3sl4 I came to wonder if anybody knows of a... kind of list, that shows equivalent SMD packages?Like, I want to create a uniform naming scheme in my libraries, but it happenes all the time that you stumble upon some strange name a manufacturer gives to a package, you implement that, only to find out that this 14PDSONWTFSOICQFP-3 thing you just created looks suprisingly simmilar to that SOIC-14 thats right beside it on your board.Not to speak about stupid things like having 5 (SO, SOIC, PDSO, R-PDSO, SOP, maybe more?) different names for the same package...So, is there some kind of reference table?And if not, maybe we should gather our knowledge and experience and start such a table?

author: jpanhalt
author_rank: Super Contributor
timestamp: December 18, 2022, 11:49:56 am
content: Now, that would be nice. Here's one place to start:https://www.microchip.com/en-us/support/package-drawingsLimit search to QFN packages. Then compare these listings:1) 40-Lead QFN 5x5 MP (C04-00047)2) 40-Lead QFN 5x5 Q9X (C04-00047)Is there a difference other than the name? Why two listings?In other words, trying to make such a catalog would be a nightmare with just one manufacturer. Expand that to all manufactures and you'd become absolutely crazy. What's the incentive? What's the payback? What's your insurance in case someone relies on your tabulation and produces a million boards only to find out the chip they wanted to use won't fit?EDIT: If you want a downloadable version, try this:http://ww1.microchip.com/downloads/en/PackagingSpec/00000049BQ.pdf

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: December 18, 2022, 11:59:51 am
content: Of course you can't provide such information for all manufacturers and their strange naming codes.In fact, I don't consider things like these special Namecodes that are often uses, like the "MP" and "Q9X" you mentioned.What I was looking out for was in that case "QFN40 (5x5)". And since that is identical, that would be fine (for me) and I would treat that as one footprint.What I was after are things likeSOT23-5 <-> SOT25SOIC8 <-> SO8and so on.Standard package names that are interchangeable and only exist because some people decided that 3 competing standards for names aren't enough, so they created a fourth competing standard to solve all problems.And - obviously - nobody should rely on information someone else provided for free, as those are just an effort to make things a bit easier, and definitely not a (paid) technical consulting.If somebody fucks up because he didn't double check information he found on some forums on the web.... well, I really couldn't care less.

author: Feynman
author_rank: Regular Contributor
timestamp: December 18, 2022, 06:19:20 pm
content: One approach would be to name your footprints according to package type and dimensions (pitch, pin length, ...). There are some conventions already out there and widely used. For example the IPC-7351B convention or the convention introduced by the third party tool from PCB Libraries. The PCB Libraries convention is what was planned for IPC-7351C, but version C of the standard was canceled eventually.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: December 19, 2022, 10:20:02 am
content: I don't know what a T3sl4 package looks like, nor how it compares to an 14PDSONWTFSOICQFP thing, but packaging for electronics components is a big mess. On top of the different names, there can be very slight pitch variations for packages with the same name. One pitfall is a pitch of 0.6mm compared to 0.63 or 0.635mm. The difference is so small you can't see it, but if you have an IC with 8 pads in a row, the pitch difference adds up and the IC won't fit on it's footprint anymore. Same for connectors. Some common connectors are available in a pitch of 5mm and in 5.08mm. The connectors will mate up to about 4 conductors, but beyond that they won't fit anymore.And it's not only packaging.Manufacturers of microcontrollers have discovered they can make more profit by dumping more senseless model diversions on the market. It costs next to nothing to add a few timers or uarts to a chip, and you can happily leave some unused. The difference is just a handful of flipflops and registers that mean nothing compared to the uC core and memory. From the consumer (engineer's) point of view usually around 90% of the offerings of a uC manurefacturer does not make any sense because they are too similar to the next model. With ST it's even more blatantly so. they sell the same uC with a bunch of different type numbers. It's not uncommon to have a uC that does not have a USB peripheral according to it's datasheet, but it does have it in hardware. Same with memory. their uC's can have twice as much flash as stated in the datasheet (but it's not guaranteed...)Same with analog IC's. Wen the TL072 and TL082 were designed some 50 years ago, there was a noise difference between them, but these days they are just the exact same opamp apart from the number burned into the top. And all the suppliers are wasting shelf space by having both of those numbers on stock. There are quite a lot of differences between opamps, but I can't imagine the differences are big enough to warrant the tens of thousands of different "models".I once did a search for a bog standard wired 1/4W 1k 5% resistor at Digikey. I could not get the selection down to less then 200 "different" resistors in any sensible way. It's just madness, and it has to be a huge senseless train on the whole supply chain.Same for consumer appliances. The microwave tube in a microwave oven has a limited lifetime. You'd think it would be a replaceable part, and there are spare parts... You can choose between some 100+ models for a 1kW microwave tube.

author: TankSparks
author_rank: Contributor
timestamp: January 17, 2023, 04:04:11 am
content: I keep adding to my notesDiode packagesDO-214AC, also known as SMA, is the smallest size.DO-214AA, also known as SMB, is the middle size.DO-214AB, also known as SMC, is the largest size.DO-214BA, also known as GF1I can't find a site that list them all.