Proposal : How could distributors make it easier to order jellybean parts - Page 1
Forum section: electronics / general

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 29, 2018, 07:37:03 am
content: Everyone who has had to do a production order on sites like Digikey, Mouser etc. will know how annoying it is to order a large number of different "jellybean" parts. i.e. standard resistors, capacitors etc. where you don't care about specific manufacturer part numbers, you just want, say, a 1K 0805 1% resistor, but the parametric search gives you a dozen options for what ( as far as you are concerned) is the same thing.You don't want to bake a manufacturer part number into your bill of materials, as that particular part could be out of stock or obsolete next time you order. This is a particular concern with the current craziness in the passives market,I've yet to see any distributor address this in any meaningful way.What I propose is this :A simple part numbering scheme for jellybean parts, where there is a standardised way of specifyingonly the parameters you care about.This number would later get translated into one of a set of pre-defined manufacturer part numbers, based on stock availability and price.Importantly, this translation happensat the point of the order getting placed, not when the part number is entered, so you could have a saved basket or BOM using the jellybean part numbers, and every time you order, these would be converted into a suitable part number based on stock available and best price at the quantity of that particular order.The translation would also know that, for example a 1% part can be substituted for a 5% one, but not vice versa, X7R can be used where X5R is specified etc.This would (at least intially) be confined to extremely generic parts, basically SMD resistors and ceramic caps. Not TH as there is too much variation in physical size.The numbering system would be really simple, butstandardised- bonus points if multiple distributors supported it.Let's Call it aJBPN(JellyBean Part Number)For example :All parts start with JB ( JellyBean), a letter to identify the type of part, a value field, a case size, and thenoptionaladditional parameters in a defined order. Some examples :JBR-4K7-0603-1P a 4k7 resistor in 0603 (imperial), 1% ( avoid % symbol because legacy systems)JBR-1.2K-0402 a 1.2K resistor, in 0402, don't care about tolerance ( 5% or better)JBC-100n-0805-16V : a 100nf 0805 cap, at least 16v, don't care about dielectricJBC-10u-1206-10V-X5 : a 10uf 1206 cap, at least X5 or X7 dielectricStandard formats :Resistors:R-nn.nnR/K/M -case[-tolerance] ( R optional ) or the standard nRnnn formCaps :C-n.nnP/N/U -case [-dielectric[-tolerance]]p,n or u for pF,nF,uF with no range constraints e.g. 10000p, 10n, 0.01u or 0u01 all specify the same partMaybe allow Mnnnn for metric case stylesAll letters case-insensitive.As doing this properly would need significant changes, I propose an interim step where you type in a JBPN into the search bar and it only returns exact matches that are in stock.As it is now, if I type 4K7 0603 into Digikey, I first have to tell it I want a resistor, then that I don't want 4.7R, 4.75K or 14.7K, and then that I don't want 0603 metric (0201)If I have a list of 20 values to order this gets very annoying. It is possible to cut/paste values into manufacturer part numbers, but this fails when that part is out of stock, and you have to guess the value format used by that manufacturer

author: bd139
author_rank: Super Contributor
timestamp: June 29, 2018, 07:43:27 am
content: Brilliant idea. I have a spreadsheet of jelly bean part numbers I use. It’s a pain in the ass. This would make it much easier.It’s kind of like the TUN/TUP stuff of Elektor. Minimum specification.Then again Pro Electron and CV numbering was supposed to do the same thing but look where that went. Every damn vendor would just register a new part number claiming minor specification variant. There was no motivation to be another CV2376 vendor.

author: Ice-Tea
author_rank: Super Contributor
timestamp: June 29, 2018, 07:55:47 am
content: I do something like that for when I send a design to a stuffer. And I clearly indicate which parts can be "JB" and which ones must match PN exactly.Never is exactly that easy, though.Resistors: thick film/thin film/surge rating/.. In addition, anything that has an influence on qualification should not be substitutedCaps/inductors: anything in, per example, an RF path shouldn't be touched.Your system makes perfect sense but I don't think Farnell/Mouser/Digi would want the responsability. In addition, if this would be implemented it's easy to predict what would happen: a race to the bottom. You will be getting Ying Ho Chow parts. I don't know about you, but I tend to avoid B-brands, even for jelly bean stuff. That option goes out the door...

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 29, 2018, 08:02:16 am
content: Quote from: Ice-Tea on June 29, 2018, 07:55:47 amStrictly only for where you don't care about these things.The idea is to makemostof the ordering process easier, so you only need to look in detail where it matters, not on every partQuoteEasy - when you place the order it shows the actual parts - it is your responsibility to check, BUT there must also be an easy way to tell them that an inappropriate part has been selected

author: nctnico
author_rank: Super Contributor
timestamp: June 29, 2018, 08:09:45 am
content: Still I'd like to use A-brand parts and not the bottom of the barrel un-branded stuff. And what is preventing a distributor to sell you the most expensive version of the jellybean part?

author: ataradov
author_rank: Super Contributor
timestamp: June 29, 2018, 08:12:10 am
content: Part manufacturers are typically very unhappy about trying to cut their part numbers out of the BOM. And distributors will not want to make their suppliers unhappy. So this is highly unlikely to happen just for that reason alone.I ran into this many times. Things that totally make sense get rejected just because it will "look" bad.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 29, 2018, 08:12:54 am
content: Quote from: nctnico on June 29, 2018, 08:09:45 amYou'd notice the price was silly, and word would get around. Look at how Digikey handles things - they will tell you if it would be cheaper to order teh next price break.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 29, 2018, 08:14:16 am
content: Quote from: ataradov on June 29, 2018, 08:12:10 amI don't care. This is about distributors offering a better service, so I use them and not a competitor.Digikey is way ahead of farnell in useability, so I use Digikey for production orders. Simples.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 29, 2018, 08:15:42 am
content: You could maybe even do this like some of the 3rd-party order plug-ins available for Digikey, to at least improve filtering of value and stock availability.

author: ataradov
author_rank: Super Contributor
timestamp: June 29, 2018, 08:16:31 am
content: Quote from: mikeselectricstuff on June 29, 2018, 08:14:16 amDistributor needs to stay in business, if all part manufacturers pull out because of their policies, they will not have any service. Unfortunately this is not some sort of fantasy, political games like this are going on all the time between suppliers and distributors.

author: ataradov
author_rank: Super Contributor
timestamp: June 29, 2018, 08:17:33 am
content: Quote from: mikeselectricstuff on June 29, 2018, 08:15:42 amIt can probably be a third-party service like parts.io, but somebody has to do that. And I'm not sure hoe to monetize it.

author: David Chamberlain
author_rank: Frequent Contributor
timestamp: June 29, 2018, 08:45:03 am
content: It's an interesting idea. But the proposed JB system lacks specificity. For example on a given design I like to stick to one cap manufacture for the entire board, or I might want to specify any part between 6 to 10 Volts knowing that the cost per unit either side of those numbers is likely to be high for given package size.I think if the system was limited to just resistance value, package size and tolerance it would have limited appeal and in doing so you are asking the suppliers to create lists of qualifying parts.If a common standard for parametric searches could be agreed upon by the various vendors then it might work. For example If I could perform the standard parametric search and save that to my cart rather than a specific component, as well as having the ability modify that parametric search later. That way I could select as many or as few parameters as I thought necessary to satisfy myself that I was not going to be sent freakish weird parts.Then the question is out of all the results what part is going to be selected? will it be the cheapest one? Will they lump in a digi-reel for 10 SMD resistors? or split 10 resistors between two manufactures.Also I don't think many can do ranges on most parameters. For example resistors in this link only the resistance can be searched between two values.https://www.digikey.com.au/products/en/resistors/chip-resistor-surface-mount/52?k=resistor%20smd

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 29, 2018, 08:54:11 am
content: Quote from: David Chamberlain on June 29, 2018, 08:45:03 amThis is missing the point. It's specifically for where you only care about basic parameters, to make ordering the bulk of the BOM easierr.It has to be very simple, to make it easy (therefore more likely) to implement.As soon as you add complication, it becomes less viable and offers less benefit.

author: Berni
author_rank: Super Contributor
timestamp: June 29, 2018, 09:06:46 am
content: That is a brilliant idea!Especially relevant in the capacitor shortage days we are experiencing.We usually do this by simply not giving the people who stuff the board any partnumber for generic resistors. Most of these smaller gig places are fine with it, but we seen places that require the exact partnumber for every resistor before they will even give a rough quote, very annoying job to go back and throw just some partnumbers in there one by one.The risk of having partnumbers associated with resistors is also that you could change the resistor value but forget to update its part number. To do it properly you need to have every resistor value in your CAD tools library.

author: David Chamberlain
author_rank: Frequent Contributor
timestamp: June 29, 2018, 09:26:59 am
content: Quote from: mikeselectricstuff on June 29, 2018, 08:54:11 amMike I think I'm not missing the point, I just did not think it necessary to add the qualifier 'for me personally' or 'in the way I select parts for my designs'Quote from: mikeselectricstuffFor example I think that part of the specification would be very hard for the distributors to implement, based on my previous statement regarding known numeric ordering of parameters.I'm not trying to be negative I just think (in my personal opinion) that selecting a specific part should be done exactly and if you find the one you like and want to call it a jelly-bean and order a full reel of them and call it done for the next few years.4k7 0603 1% on digikey + in-stock + sort by cheapest we findSamsung RC1608F472CSso 3000 for AU$27.45

author: Berni
author_rank: Super Contributor
timestamp: June 29, 2018, 09:39:57 am
content: Well in that case you have to ship the reel to the place that populates the boards and what they didn't use they ship back to you. Its extra logistics.This is simply a nice way of telling the supplier to just take the cheapest part that fits the bill at a supplier they want. If you only need a 10V capacitor but a 16V part is cheaper? Great take it.For critical capacitors such as on the output of a switchmode regulator you would NOT use this. There just find the capacitor with the right specs and put down the full partnumber just like you do now (And perhaps 1 or 2 alternative parts just in case).

author: tszaboo
author_rank: Super Contributor
timestamp: June 29, 2018, 10:00:15 am
content: I have a large resistor library filled with descriptions like this:RES SMD 3.48M OHM 1% 1/16W 0402RES SMD 3.57M OHM 1% 1/16W 0402RES SMD 3.6M OHM 1% 1/16W 0402RES SMD 9.53K OHM 1% 1/4W 1206RES SMD 9.76K OHM 1% 1/4W 1206CAP SMD 0603 150 pF 10 V NP0CAP SMD 0603 220 pF 10 V NP0CAP SMD 0603 330 pF 10 V NP0OK it is not perfect.And I assigned a manufacturer number to each of these.And mark them with the industry standard F code, meaning:F2 I dont careF1 send me a question in email if you want something elseF0 It has to be that partOtherwise, just let the assembler buy the jellybean parts for prototypes.

author: amyk
author_rank: Super Contributor
timestamp: July 02, 2018, 04:45:43 am
content: This is something that I don't see being feasible without state-level dictation over the part numbering system. The Chinese have the CDxxx standard for electrolytic capacitors. The former Soviet countries had their own national standard for ICs and other parts.

author: ataradov
author_rank: Super Contributor
timestamp: July 02, 2018, 04:56:48 am
content: Quote from: amyk on July 02, 2018, 04:45:43 amWhy? The whole proposal works around any standards. Manufacturer creates whatever part number they like, distributors also have their own part numbers. Imagine if distributor also created a "universal" part number. So all components from all manufacturers with the same set of basic characteristics have the same virtual part number. Now you search for that virtual part number and you can ether see all parts that match it, or just have it as a line item and a random (cheapest?) part gets delivered.It is like having "7805-TO220" as a virtual part number for a 5 V voltage regulator in a TO-220 package. I want to order that part number and get whatever manufacturer has the cheapest one this day.

author: KE5FX
author_rank: Super Contributor
timestamp: July 02, 2018, 05:07:06 am
content: Quote from: ataradov on June 29, 2018, 08:12:10 amThen they can damned well manufacture and ship those parts. I grow less sympathetic to this argument every time I search DigiKey for a bog-standard 0402 capacitor and get responses like "42 week lead time."Those manufacturers are encouraging -- actually more-or-lessrequiring-- the industry to come up with a layer of indirection like Mike proposes to work around their "politics." If they want to be in a race-to-the-bottom commodity business, they're doing everything necessary to make it happen.

author: Berni
author_rank: Super Contributor
timestamp: July 02, 2018, 05:07:21 am
content: It would be nice to have a similar thing for jelly bean chips but things can get more complicated there. Its possible to have jellybean chip variants that are almost the same but not quite the same. Its also easier for a distributor to make a mistake and group a part under one jellybean part number that should not be there because the package is slightly different or something.But SMD passives are so standardized that its hard to mess it up. Unless your design is so space constrained that the height of SMD capacitors matters, in that case again use the old way of giving the full partnumber to the exact part. (And i had designs where space was this tight)

author: julianhigginson
author_rank: Frequent Contributor
timestamp: July 02, 2018, 05:17:58 am
content: Mike, the original post sounds like a good idea, but the issue is that no matter how many standard parameters you want to have, someone will have an application for something you never thought of... then someone will take your system, add in capability to cver that thing, and release their own fork of it. And then someone will find an application where some other parameter never before considered for just a specific subtype of a component kind needs to be notated..... and then you have a third version of the system... see where I'm going here?My solution is similar to NANDblog..I have a parts database with real specific defined parts in it... which means for a design I can *always* put in a specific and known part that fits the purpose. This means that no matter what, if a product is built with my listed parts, it's going to work.then in the schematic, I will have a field for each part that says in that particular application if the exact part is required, or if a sub is OK, or if any possible sub would need discussion.

author: ajb
author_rank: Super Contributor
timestamp: July 02, 2018, 05:35:45 am
content: I've added an alternate PN field to my parts database that gets inserted into my BOMs, and any time I have to pick an substitute part it gets added to the list. It's not perfect, and if I were doing it again it would be a good idea to pick specific archetype specs that are easy to cross, rather than try to match whatever particular part I picked last time as closely as possible, but it certainly helps and it's something I can do piecemeal. With the MLCC market being what it is right now, I've taken to adding every suitable part number I can find whenever I send out a CM package because who knows what will be out of stock by the time the CM sends out their POsAnyway, the key to making anything like this work is going to be a sufficiently easy to use central repository. Seems like the kind of thing Octopart would be good for, actually.

author: maginnovision
author_rank: Super Contributor
timestamp: July 02, 2018, 07:22:34 am
content: This is a very good idea for the current climate of 1 year backorders. When I build my boms I basically add the first part that matches spec and then when I got back 2 months later I have to change it to another. Specifying the basics would be really useful, possibly adding mfgrs to an approved list so you don't get stuck with garbage.

author: Cubdriver
author_rank: Unknown
timestamp: July 04, 2018, 09:06:51 am
content: I use a similar part numbering scheme for my BOMs for work - resistors and caps that can be considered 'jellybean' get an in-house generic part number that, for resistors, is Rxxxxyyy-z-vvvv, with the Xs being the SMD package size (inch), Ys being power rating, Z tolerance and VVVV a four digit value.For example, a 33.2 ohm, 1/16W 1% 0402 resistor would be R0402063-1-33R2A 4.75k, 1/8W 1% 0805 part would be R0805125-1-4k75. (In hindsight, I should have put another dash between package size and tolerance, and may change things at some point)Ceramic caps get a similar treatment - Cxxxxyyyzzz-vvv, again with Xs being package size, Ys being dielectric, Zs voltage and Vs the value.C0603X7R050-10n is a 0.01uF, 50V X7R cap in a 0603 package.C0402C0G050-1p0 is a 1pF, 50V C0G cap in a 0402 package. I need to add tolerance to the cap part number at some point.Suffixes may be added to the generic numbers for special cases, such as expanded temperature ratings, if needed. These generic part numbers are then linked to vendors and manufacturer's part numbers in my database, and I buy what's convenient or available at the time I need it.-Pat

author: a59d1
author_rank: Regular Contributor
timestamp: July 05, 2018, 05:56:36 am
content: This is a great idea, Mike, and I'm going to steal it. I'll let you know when the demo service is available.

author: hans
author_rank: Super Contributor
timestamp: July 05, 2018, 05:03:15 pm
content: I've got a local service running that scrapes some suppliers websites for all passive components they have got.Then made a simple search engine such that I can query them, e.g. "r 0603 10k 100qty" will give me all 10k resistors in 0603 package with >100qty in stock, sorted by price for that price bracket. For some suppliers it also removes external inventories and rereel options, as for prototyping I never needed this.Actually it's wouldn't be hard to tie a part number system to this, as both contain the same info.But as said, it's still a local running service while I'm still prototyping it. One small problem is that some of these manufacturing websites are so damn slow to load, that it literally takes a full week to index all product listings that contain these passives, assuming only a single thread/connection... But if I multi-thread, then I'm afraid I will get timeouts or refused connections.I wish they would just offer all their part specification database as a CSV. I think Digikey at one time did, but I rarely order there due to shipping costs..

author: David Hess
author_rank: Super Contributor
timestamp: July 05, 2018, 06:43:03 pm
content: I do that myself anyway when I make up parts lists. I have my own mnemonic part number which translates into qualified manufacturer's part numbers.