Small cheap 3 pin SMD socket - Page 1
Forum section: electronics / projects

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 03:14:40 am
content: I'm looking for a 3 pin socket to use as a programming port on a project I'm designing.Must be:-Small-Surface mount-Connect parallel to the PCB (Horizontal)-Cheap in 100 quantitiesMore than one source would be nice since I anticipate wanting to make these for several yearsIt doesn't need to be particularly rugged as it will only ever be used once or twice, but the plug the connects to it does need to be decent and it will be used many times.What I've found so far is this 3.5mm socket, which has the advantage that I can use off the shelf cables for the programmer.http://au.mouser.com/Search/ProductDetail.aspx?R=161-3934-Evirtualkey11180000virtualkey161-3934-EI've pretty much decided on this, but I haven't been able to find another source, and I'd prefer something cheaper if possible.Does anyone have any suggestions?

author: kingofkya
author_rank: Regular Contributor
timestamp: August 28, 2014, 03:52:04 am
content: Why not just standard pin headers? I don't think you can get mutch cheaper than that, and you can get them keyed if needed.http://mouser.com/ProductDetail/Molex/171857-1003/?qs=sGAEpiMZZMs%252bGHln7q6pmySggPlC%2fDRbgQFC88fsCbY%3dYou can get much better prices than that, on generic ones.http://www.taydaelectronics.com/connectors-sockets/wafer-housing-crimp-terminal/serie-2400-3-96mm.htmlOr one of thouse pcb edge connectors thous are free on the device side. And the common ones like pcie-x1 are cheap. most are not smd though.http://www.digikey.com/product-search/en?FV=fff40016%2Cfff80093&mnonly=0&newproducts=0&ColumnSort=1000008&page=1&stock=0&pbfree=0&rohs=0&quantity=&ptm=0&fid=0&pageSize=100I was going to play with a few of theseshttp://www.digikey.com/product-detail/en/EBC06DCWN/S3293-ND/927245

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 04:17:23 am
content: Thanks for your reply.Quote from: kingofkya on August 28, 2014, 03:52:04 amIt must not protrude from the bottom of the PCB so SMD is my only real option.QuoteThat's something I had thought of, but it would require the bare connections to be exposed. I can't have that. Otherwise, this would be ideal.http://www.digikey.com/product-detail/en/368-004-520-201/368-004-520-201-ND/2522104QuoteBut not small enough.

author: Mr.B
author_rank: Unknown
timestamp: August 28, 2014, 04:28:05 am
content: Quote from: Mike Warren on August 28, 2014, 04:17:23 amSurface mount pin headers are common, even in 1mm pitch if you want really small.

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 04:39:30 am
content: Quote from: Mr.B on August 28, 2014, 04:28:05 amYes, I see them in all sorts of equipment, but I guess I don't have the right search parameters for Mouser or Digikey. Anything I can find even approaching what I'm after goes through the roof, price wise. And yet, I see these sorts of things used in very cheap equipment.For 3 pins I could even go as large as 2.54mm spacing.Thanks for your reply.

author: JSnyder
author_rank: Contributor
timestamp: August 28, 2014, 04:41:29 am
content: How about a JST- type smt right angle connector such ashttp://uk.farnell.com/jst-japan-solderless-terminals/s3b-ph-sm4-tb-lf-sn/header-smt-right-angle-2mm-3way/dp/9492623?

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 04:50:56 am
content: Quote from: JSnyder on August 28, 2014, 04:41:29 amThanks for the suggestion. $2.46(100+) from E14 and non-stocked by Mouser, but Digikey have them for $0.65. It's probably not enough cheaper than the 3.5mm socket to justify the greater complexity of the programming cable.But something to think about.

author: JSnyder
author_rank: Contributor
timestamp: August 28, 2014, 05:20:19 am
content: Quote from: Mike Warren on August 28, 2014, 03:14:40 amAre you referring to connector on the cable?If your only going to use it a couple of times as a programing header, why add the cost of a per-board connector into the BOM? you can use exposed pads and a programming cable with pogo pins, or a programing cable terminated with standard pin header and a matching footprint on the board. Just stick the pin header in the holes on the pcb and manually hold it while flashing, remove it when done. Just throwing out ideas, sorry if I'm way off base

author: true
author_rank: Frequent Contributor
timestamp: August 28, 2014, 05:26:00 am
content: As the previous post said, why not just pads+pogopins?But that said, why are you looking at the standard distributors for high-priced mechanicals? You are using it once or twice per board. Get a good quality cable and look for the cheapest crap you can find on eBay or some other web seller. Terrible example buthttp://www.ebay.com/sch/i.html?_from=R40&_trksid=p2055845.m570.l1313.TR0.TRC4.A0.H0.X100pcs+jst+panel.TRS5&_nkw=100pcs+jst+panel

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 05:27:53 am
content: Quote from: JSnyder on August 28, 2014, 05:20:19 amYes.QuoteThis is for use by the end users to dump EEPROM configuration data to the device. They would buy a programming interface, cable and software that allows custom configuration and then plug it in to the devices. I would estimate 1 programmer set up to every 100 to 1000 devices over maybe a 5 year period.I already do my actual programming of the micro with pogo pins.Thanks for your input.

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 05:31:09 am
content: Quote from: true on August 28, 2014, 05:26:00 amBecause I want to be able to get them over a period of several years.But if I can get something that's pin-compatible I could do that. I hadn't thought of that. I'll do some eBay searches now. Thanks.

author: poorchava
author_rank: Super Contributor
timestamp: August 28, 2014, 05:52:06 am
content: JST connectors. Chinese knockoffs are ridiculously cheap.

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 05:58:59 am
content: Quote from: poorchava on August 28, 2014, 05:52:06 amThanks for the suggestion. Do you have a link to something?

author: Gribo
author_rank: Frequent Contributor
timestamp: August 28, 2014, 08:33:44 am
content: A quick search on mouser gave me this:http://il.mouser.com/Connectors/Headers-Wire-Housings/_/N-ay0lo?P=1z0x3z7&Keyword=1.25mm+wire+to+board&FS=True

author: sleemanj
author_rank: Super Contributor
timestamp: August 28, 2014, 12:56:44 pm
content: Mini USB, crazy cheap, available anywhere, surface mount, tiny - nobody said you HAVE to use them as a USB connector, just make up your own cable/dongle/whatever.Although if it's end-user visible, they might try to plug it into USB, so you'd want to make it so that no-harm was done if that was the case.

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 09:59:34 pm
content: Quote from: Gribo on August 28, 2014, 08:33:44 amThanks, but any of those that are suitable fro my application are more expensive than the 3.5m sockets from Mouser.

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 10:01:12 pm
content: Quote from: sleemanj on August 28, 2014, 12:56:44 pmThanks for the suggestion. I would love to be able to use mini USB, but the risk of damaging someone's computer is too great.

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 10:09:09 pm
content: Searching eBay, looks like this would be almost ideal. The price is perfect.http://www.ebay.com/itm/1000PCS-4Pin-SMD-1-8-3-5mm-Headphones-Stereo-Jack-Socket-PCBs-Panel-Mount-PJ321-/141068417868?pt=LH_DefaultDomain_0&hash=item20d8553b4cThe only issue I have is whether these are packaged for pick and place. I suspect not.I've also looked on Alibaba, but no one seems to list any prices. There must by many Chinese suppliers that would have something suitable.This style may be good as there seems to be lots of different suppliers selling what looks like the same thing, but I can't find anyone with a deal approaching as good as the one above.http://www.ebay.com.au/itm/50-PCS-6-Soldering-Pin-3-5mm-SMD-PCB-Stereo-Jack-Female-Connector-Socket-Yellow-/400752181572?pt=LH_DefaultDomain_15&hash=item5d4eb10144

author: rs20
author_rank: Super Contributor
timestamp: August 28, 2014, 10:17:34 pm
content: Oh God. A thread where there have been suggestions both to use a 3.5mm AUDIO cable for something that's not audio, and a mini-USB cable for non-USB purposes. "Make sure it doesn't blow up if you plug it into USB" -- never mind device damage, don't you care about user confusion? It's like labelling the on button with "off", and noting the discrepancy down in the fine-print of the manual. I don't care if the electrons don't care, it's a confusing user experience and looks super-amateurish. Running away...To be fair, I don't know the specific end-use here, but I'm not sure I can imagine one that justifies such horrors.

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 10:26:07 pm
content: Quote from: rs20 on August 28, 2014, 10:17:34 pmI consider the risk of using 3.5mm very low since if someone plugs anything (headphones, audio player etc.) into this no damage will be done. However, plugging a computer in via USB does risk damage because of the power being supplied via the USB cable.Also, these do connect to a computer (through an interface), so many people would think it logical to connect USB directly. So that's why USB is completely out of the question.

author: JSnyder
author_rank: Contributor
timestamp: August 28, 2014, 10:29:00 pm
content: Quote from: rs20 on August 28, 2014, 10:17:34 pmHence my suggestion, I filled all of the requirements listed. OP if you were dead set on using stereo jacks why did you bother asking for suggestions in the first place?

author: Mike Warren
author_rank: Unknown
timestamp: August 28, 2014, 10:46:29 pm
content: Quote from: JSnyder on August 28, 2014, 10:29:00 pmI'm not dead set on using 3.5mm jacks. Your suggestion didn't fit one of my requirements, which is price.In a perfect world I would use something like this and a custom made cable:http://il.mouser.com/ProductDetail/Molex/504195-0370/?qs=sGAEpiMZZMs%252bGHln7q6pm58uVUMQZrFtsGEhKmnRnJUaIG6dvNjntw%3d%3dBut, it has 2 disadvantages: too expensive and requires a custom cable to connect to the computer interface.At this point, 3.5mm stereo socket (now that I'm beginning to find cheap ones) solves those, but has a slight risk that someone will plug audio equipment into it.Considering the context these will be used in, that is quite unlikely, but even if someone did that, no damage would be done to anything.The only risk is that someone could plug in the 3.5mm cable from the interface into an audio device. Even then, the risk of damage is not great as the voltage on the line is only 3.3V and current limited to 15mA.

author: westfw
author_rank: Super Contributor
timestamp: August 28, 2014, 11:09:19 pm
content: QuoteIt shouldn't, if you only need 3 of the 4+ connections that USB provides. Leave VUSB+ unconnected.What about an FPC connector? likehttp://au.mouser.com/ProductDetail/FCI/HFW4R-1STE9LF/?qs=sGAEpiMZZMs7i6cT6ogu4xCAcU97Lcm6UdXcPNdqkLc%3dCompact, cheap, obviously not "general purpose." the big disadvantage is probably that the thin PCB you'd want to use for the other side is not very robust...

author: Mike Warren
author_rank: Unknown
timestamp: September 05, 2014, 02:07:19 am
content: Quote from: westfw on August 28, 2014, 11:09:19 pmThanks for your reply.I can still see it causing problem when people think they can plug it directly into their computer.QuoteYes, the other end is the part that needs to be reliable as it will be used on lots of devices. That connector is still not much cheaper than the 3.5mm socket I was looking at originally.

author: Mike Warren
author_rank: Unknown
timestamp: September 05, 2014, 02:23:15 am
content: I've talked to my assembly place and they say they can handle loose parts economically, which has made me look further into the idea of the cheap eBay and Alibaba sockets.I think going to 2.5mm will reduce the casual occurrence of plugging headphones and audio devices into it, and have found this from China. The only downside of 2.5mm compared to 3.5mm is that there are very few cheap off-the shelf cables available, that I've been able to find.http://koumay.en.alibaba.com/product/1654572344-219578306/2_5mm_SMD_SMT_Female_Phone_Jack_PJ_223.htmlI've asked for a quote and they came back to me quickly with a cost of US$75 per 1000, which is a good price, and US$53 for DHL freight, which is not so nice. They've even offered to supply some free samples.Never having dealt with Alibaba suppliers before, I'm not confident I know how to look out for the scammers, but nothing looks off to me.Does anyone see anything that might make it suspect?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: September 05, 2014, 02:30:41 am
content: How about no connector at all?http://www.tag-connect.com/

author: Mike Warren
author_rank: Unknown
timestamp: September 05, 2014, 02:34:48 am
content: Quote from: Alex Eisenhut on September 05, 2014, 02:30:41 amThanks for the suggestion. Unfortunately, I cant have any exposed board where something might short out on it in use.

author: Aleksolder
author_rank: Contributor
timestamp: September 05, 2014, 03:20:01 am
content: Like true said, this is something that China is good enough for. I buy on alibaba, though I admit that so far only for stuff they can't screw up.1x40 right angle TH $US 13 for 200pcs, that's $US 0.005 per 3 pins, and these are going to be around forever, many purchase options for cabling.Above price was TH, here's the SMD version:www.karlssonrobotics.com/cart/6-pin-right-angle-male-smd-header. Send this image to your fab, ask what he can do, he probably has a cousin who makes them.

author: Mike Warren
author_rank: Unknown
timestamp: September 05, 2014, 03:48:17 am
content: Quote from: Aleksolder on September 05, 2014, 03:20:01 amThanks for your reply. I can't have anything with exposed terminals.I've been exchanging emails with the company I mentioned above, and they seem legit. Also, it turns out that they will be supplying them on reels, so I'm happy that my problem is solved. I've just ordered 2000 of them to reduce the total unit cost.Thanks to all who responded.

author: westfw
author_rank: Super Contributor
timestamp: September 05, 2014, 05:23:45 am
content: QuoteI'd sort-of worry, because there's a lot of engineering that goes into connectors that is obscure to my EE/CS mentality.It probably doesn't matter too much in this case, since you said that programming will be relatively uncommon, but I've seen big differences in (one example) SAMTEC connectors and the cheap similar connectors that are being sold as "stacking connectors" for Arduino/etc. Things like mechanical robustness and tolerance, plating and base materials, insertion/retention force, springiness, insertion cycle rating, corrosion resistance, and so on. Things that one doesn't normally think of when buying chips that either work or not.I had a bit of an interesting conversation with a connector manufacturer at a trade show last year, who was happy to find an ear that was at least slightly interesting in hearing the explanations of high-retention USB vs normal, and how micro-usb was the first USB connector that was "done right" because the springy bits (that wear out) were in the cable (easy to replace) instead of the PCB-side connector (which is soldered onto an expensive product.)(I also own an outdoor sprinkler controller whose connectors (3.5mm jacks, in fact, I think) turned out to just NOT be quite up to the task of being outdoors. After a year, enough moisture had seeped in to cause enough corrosion that the plugs were no longer even retained, much less capable of forming reliable electrical connections. :-( )

author: Mike Warren
author_rank: Unknown
timestamp: September 05, 2014, 05:29:53 am
content: Quote from: westfw on September 05, 2014, 05:23:45 amIn 99% of cases it only ever will be used once, before the device is put into service. That's why having it as the most expensive part on my BOM was driving me nuts. I think these will be perfectly fine for the job.

author: Mike Warren
author_rank: Unknown
timestamp: September 11, 2014, 03:52:39 am
content: Two reels of 1000 2.5mm stereo SMD sockets have just arrived. I've examined and tested a couple, and they look well and truly good enough for the purpose.Total cost, landed: US$0.11 each. And the sales person at the company was very good to deal with.