Do you use SO8 to DIP8 socket? is it perfect?  - Page 1
Forum section: electronics / projects

author: loop123
author_rank: Frequent Contributor
timestamp: February 04, 2024, 10:45:06 pm
content: I have a chip I need to try on existing board and the chip s no longer available in DIP8 but only in SOIC8. If I used such adaptor above. Is it perfect, or would it introduce for example more noises?

author: Benta
author_rank: Super Contributor
timestamp: February 04, 2024, 10:51:22 pm
content: Don't overthink things. Just use it.

author: coppercone2
author_rank: Super Contributor
timestamp: February 04, 2024, 11:12:17 pm
content: I used it for a dc/dc converter chip it worked fine (16 pin version)it might cause a problem if your product is on like the absolute verge of failing a EMC test and bump up the noise by a hair.

author: loop123
author_rank: Frequent Contributor
timestamp: February 04, 2024, 11:55:30 pm
content: It's just that the top of the adaptor (see original pic) has no many metals. Can't it form impedance or inductor or self resonate resulting in noises?

author: jpanhalt
author_rank: Super Contributor
timestamp: February 04, 2024, 11:58:29 pm
content: With the information you provided, how do you expect a reasoned answer to those questions?

author: coromonadalix
author_rank: Super Contributor
timestamp: February 05, 2024, 12:14:06 am
content: another crap thread ?

author: bdunham7
author_rank: Super Contributor
timestamp: February 05, 2024, 12:29:21 am
content: Quote from: loop123 on February 04, 2024, 10:45:06 pmWhich one?

author: loop123
author_rank: Frequent Contributor
timestamp: February 05, 2024, 12:40:07 am
content: Quote from: bdunham7 on February 05, 2024, 12:29:21 amThe OPA602. It's no longer available in DIP8 package but only in SOIC 8. Seehttps://www.digikey.com/en/products/detail/texas-instruments/OPA602AP/251159It will be used in a Sully-Key low pass filter to acquire microVolt signal so need to avoid noises.Please summarize what exact noises are introduced by the converter.

author: coppercone2
author_rank: Super Contributor
timestamp: February 05, 2024, 01:33:30 am
content: its going to do next to jack shityou can get higher quality metal ones (like bronze or something) from digikey that have stronger legs

author: bdunham7
author_rank: Super Contributor
timestamp: February 05, 2024, 01:41:38 am
content: Quote from: loop123 on February 05, 2024, 12:40:07 amI have no idea and it would depend on the environment. I would guess it wouldn't be a problem but with an existing design, if it were me I'd use an adapter that maintains the same orientation and has a much shorter overall lead length.https://www.digikey.com/en/products/detail/chip-quik-inc./PA0001C/12352144

author: coppercone2
author_rank: Super Contributor
timestamp: February 05, 2024, 01:54:58 am
content: that is a good observation I did not notice its rotated 90 degrees. I would not buy that one if I was choosing them. Not sure if there is a mechanical benefit to rotating it when you socket and unsocket it, but I recommend using a mild lubricant for sockets anyway (deoxit grease or similar), then its not an issue (for sockets).The only thing to watch out for is some of them are built with round pins, and others have square pins. I had a feeling some of them might damage sockets.

author: loop123
author_rank: Frequent Contributor
timestamp: February 05, 2024, 02:22:46 am
content: I need the OPA602 that is now only available in SOIC to put in an existing Sulley-key low pass filter that uses the LF411CP. What is the best op-amp in the world that you can replace in the 2 pole Sulley-key low pass filter and available in DIP. But if you know the best chip to use that is also SOIC. it's ok.

author: coppercone2
author_rank: Super Contributor
timestamp: February 05, 2024, 02:41:15 am
content: I would just try that one its a good chip and the adapter is going to do precisely jack shit to that low pass filteryou are worrying about nanovolt problems

author: loop123
author_rank: Frequent Contributor
timestamp: February 05, 2024, 02:53:30 am
content: It is to remove 20-mv p-p ripples from a carrier frequency of 500kHz. Therefore any unwanted path might cause other distortions. So consider the application is Milspec.

author: coppercone2
author_rank: Super Contributor
timestamp: February 05, 2024, 03:16:07 am
content: that usually means something about withstanding damage and passing certain very specific tests

author: BrokenYugo
author_rank: Super Contributor
timestamp: February 05, 2024, 04:07:51 am
content: With the size of a DIP8 adapter board I'll hazard a guess any parasitics induced by it would only matter with parts that are way too fast for through hole.

author: TERRA Operative
author_rank: Super Contributor
timestamp: February 05, 2024, 05:02:49 am
content: Unless you are working with nano-volt levels or GHz speeds, the adapter will be fine. You are adding less than half an inch to the total trace length.If you really want to make it better, pull the plastic off the header pins, solder the adapter flat to the main PCB then cut the extra length off the legs.Orientation compared to the original part won't matter, and soldering flat on the PCB will mean a good portion of the join between the main PCB and adapter PCB will be pad-solder-pad, and your components are using solder anyway, so.... no problems.

author: bdunham7
author_rank: Super Contributor
timestamp: February 05, 2024, 05:15:57 am
content: Quote from: loop123 on February 05, 2024, 02:53:30 amI'm pretty sure you could do that on a breadboard, so the SOIC adapter should be fine.Mil-spec?

author: coppercone2
author_rank: Super Contributor
timestamp: February 05, 2024, 05:17:38 am
content: I warn people about mil spec because its marketing wank. Usually it means that it can work better in antarctica or a hot day in the sahara. A noisy 741 is mil spec if it gets the -40 c temp range.There is nothing mil spec about some of the best most sensetive scientific equipment in the world, it just means it has to be in doors in a habitable environment.The only time I would be interested in mil spec is if its supposed to be somewhere treacherous.infact usually you would argue that mil spec focuses the efforts in a direction other then science, which is military crap. That's how scientific discoveries are being made with bearly functioning unreliable lecroy oscilloscopes and suchit means gaskets, frost, ovens and shaking

author: Infraviolet
author_rank: Super Contributor
timestamp: February 05, 2024, 11:03:30 pm
content: If anything, this adapter will add back in the inductance you would otherwise lose when going from a DIP to an SOIC. I've used similar things a lot and never had any trouble. Do remember though, that the pins on the adapter are header size pins, and not as narrow as the legs of DIP chips. It will probably fit the size of through holes on a PCB you'd usually leave for DIP chip legs, as you usually leave relatively big holes, but it will not fit in to a DIP carrier socket, and won't fit a PCB if the DIP chip's through holes were made as narrow as they can possibly be for DIP legs."Milspec" is about surviving being treated roughly in rotten environments, so long as the PCB itself is securely held inside a toughened case and the electrical inputs/outputs entering/leaving that case have appropriate protection from ESD or being connected to the wrong voltage which just happens to have a similar style of lead to the one the user is supposed to connect, then I'd say just about any circuit can probably be "milspec". Whether DIP or SOIC or SOIC on DIP adapter would make no difference here.

author: Benta
author_rank: Super Contributor
timestamp: February 05, 2024, 11:51:32 pm
content: You'll need the knowledge of the OP from another thread to correctly catagorise this one:https://www.eevblog.com/forum/beginners/can-changing-amplifier-in-sullen-key-filter-affect-the-frequency-response-much/

author: zapta
author_rank: Super Contributor
timestamp: February 06, 2024, 01:00:39 am
content: > that is a good observation I did not notice its rotated 90 degrees.You can make your own non rotated custom adapters (e.g. with bypass caps). I make them from 0.8mm PCB and cut with aviation snips. I get 5 PCBs from JLC for about 4$ shipped and they last forever.https://github.com/zapta/smd_adapters

author: David Hess
author_rank: Super Contributor
timestamp: February 06, 2024, 01:29:58 am
content: The SO-8 to DIP adapter will work fine. If you want it to be socket compatible, use the correct headers:https://www.mouser.com/ProductDetail/575-643506

author: loop123
author_rank: Frequent Contributor
timestamp: February 07, 2024, 01:44:31 am
content: Please tell me. Is it better if the Offset Voltage Max is higher or lower? Is +-1000uV or +-2000uV better? Because id just get the DIP8 version second hand to avoid soldering as I don't know how to solder something so small. Thanks.

author: coppercone2
author_rank: Super Contributor
timestamp: February 07, 2024, 02:54:52 am
content: smaller is better