hybridfree/eevblog-posts huggingface dataset:
Solder mask oversizing for various components? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: June 26, 2021, 12:56:35 pm
content: Hi,The following Micro USB connector (below) has a pad to pad gap of 0.15mm in places. Would you say it is possible to get solder resist between such pads? (to stop shorting between pads at solder bath time).If it is possible,(to get solder resist between the pads) then the solder mask oversize would be very small round the pad. Such an oversize would generally not be applicable to other parts on the board (eg 1206 resistors). A 1206 resistor would generally have a 0.14mm solder mask oversize.So that means you have different solder mask oversizing for different pads on the PCB…..the problem is that most PCB layout programs cannot handle such things (ie they can only give one solder mask oversize, and apply this to the entire board).So how do you manage this situation?Do you simply define your solder resist to be the same size as whichever pad, and then hope that the PCB manufacturer does a good (custom) solder mask oversize for every single pad?How many people subscribe to the theory, that when a SMD part is below a certain size, then its simply a bad idea to use any solder resist, because the solder resist may hold the part up off the board and prevent it from “settling” onto the pads at solder bath time?….if you subscribe to this, then how small does an smd part have to be before you say it should not have any solder resist?Micro USB connector (2173157-3 (TE))https://www.te.com/commerce/DocumentDelivery/DDEController?Action=showdoc&DocId=Customer+Drawing%7F2173157%7FA1%7Fpdf%7FEnglish%7FENG_CD_2173157_A1_2173157-C_revA1.pdf%7F2173157-3

author: Skashkash
author_rank: Regular Contributor
timestamp: June 26, 2021, 01:15:54 pm
content: Jlcpcb (as an example) has a minimum solder mask sliver as .05mm(wrong)I'm assuming that's for their standard service.https://jlcpcb.com/capabilities/CapabilitiesI do prefer to have solder mask between pins if I can get it. In my experience it does seem to help with avoiding shorts/bridging. For very fine pitch parts like some QFNs, it's less helpful. This is for small batch, hand or reflow oven soldering.All the PCB layout packages I've used have had the ability to specify the mask expansion on a part, or pad by pad basis. The actual mechanism may vary by tool, but even in the worst case I could do a custom pad stack and set the mask opening size exactly.UPDATE:Sorry, I misread the spec, JLCPCB is actually .2mm min soldermask sliver.
Board review request (frequency converter) - Page 1
Forum section: electronics / general

author: m4rtinpf
author_rank: Newbie
timestamp: June 29, 2021, 09:39:56 pm
content: I've designed a PCB and was looking for some review and advice. The images are attached to this post.The board is for an up/down frequency converter. Specifically, from 0-300 kHz to 400 MHz.It's a simple design, the input signal gets multiplied by a 400 MHz square-wave (X1) by a mixer (U6 or U2). There are also two LPF and limiters.Power comes from a USB connector or a terminal block and gets regulated down to 3.3 V by U5.I'm planning to get it fabricated by JLCPCB, including the assembly of the SMT parts that they carry. I would have to hand-solder the ICs (or get someone to it). It's a two-layer board, and I need a single unit.The size of the board is due to the enclosure I'm gonna use (Hammond 1455L801).I have a few questions:1. The ground plane is split in two places:- The (amplified) clock signal (400 MHz square-wave) from U4 to C3, so VCC can get to the other side of this trace.- The down-converted signal (<300 kHz) from U6 to L2, so this trace and the input signal (400 MHz) can cross.Is this OK or using 0R resistors would be better?2. Should I remove the solder paste from the ICs that I'm not getting soldered by JLCPCB?3. Are the vias connecting the top-layer filled zones to the ground plane enough and well placed (besides the ones under the ICs, just followed the datasheets for those)?Thanks for any help in advance!PS: There is a minor misalignment between layers in the images. It's because of a bug in Kicad that makes it so silkscreen is under copper when plotting to PDF, so I had to manually stack the individual layers.Edit:I've noticed that some ICs (the ones that I made the footprints for, X1 U3 U4 U7 Q1 U5) have thermal relief ("spokes"), but the rest don't. Should I add it to all of them? Remove it?

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: July 01, 2021, 06:01:02 am
content: You should move this into the projects forum, will get more traction there

author: m4rtinpf
author_rank: Newbie
timestamp: July 02, 2021, 09:10:28 pm
content: As suggested, I've posted this on Projectshttps://www.eevblog.com/forum/projects/board-review-request-(frequency-converter)-284654/
EasyEDA (JLCPCB) no so easy 100nF - Page 1
Forum section: electronics / general

author: PerranOak
author_rank: Frequent Contributor
timestamp: June 27, 2021, 04:49:36 pm
content: I have a two layer board with a through hole chip on the top. I want to put an SMD 100nF cap between the Vcc and ground pins of this chip on the bottom layer.The problem is that when I flood the copper on the bottom, of course, the ground side of the cap is just connected to the copper layer not specifically to the chip's pin.Does this matter?If so, how do you force it to connect directly?Cheers.

author: PlainName
author_rank: Super Contributor
timestamp: June 28, 2021, 06:13:17 pm
content: Perhaps doesn't solve your problem, but generally where I use a flood fill (as opposed to a plane) I route using normal tracking before applying the fill. That ensures that everything is connected regardless of fill, and there are no lengthy circuitous paths or wafer-thin connections (or, at least, none that I don't know about).

author: thm_w
author_rank: Super Contributor
timestamp: June 28, 2021, 09:19:10 pm
content: Doesn't matter. The flood is low impedance enough.Depending on your PCB software they may have a DRC rule for minimal flood thickness to avoid wafer-thin connections.

author: PerranOak
author_rank: Frequent Contributor
timestamp: June 30, 2021, 10:29:36 am
content: Thank you both.
What is a PSS simulation?  - Page 1
Forum section: electronics / general

author: steamedhams
author_rank: Regular Contributor
timestamp: June 29, 2021, 09:22:23 am
content: What is a PSS simulation?For example, when I went to see how a comparator works over a given time frame... what is the PSS simulation showing me exactly??

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: June 29, 2021, 11:16:12 am
content: I would expect PSS to be periodic steady state. It's related to Harmonic Balance simulations in that it focuses on oscillating structures, or narrow band signals.It looks at repetitive situations (in a discrete simulation, if all your information at a certain timestep is the same as a number of timesteps ago, you've reached steady state in a sense).
Is Mentor PADs standard available as a free download? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: June 23, 2021, 05:23:35 pm
content: Hi,Since Mentor PADs is out of date and now replaced by PAD pro, is Mentor PADs standard now a free download?I can find lots of sites offering mentor PADS standard as a free download but they seem dodgy, and try to get you to download other weird stuff first.Do you know where i can download a good Mentor PADs standard? (for free or a small price)

author: Feynman
author_rank: Regular Contributor
timestamp: June 23, 2021, 05:36:51 pm
content: You'll get a free PADS Standard license, if you buy PADS ProfAt least that's what we were told when we considered buying PADS Prof two years ago.Hard to believe that PADS Standard is a legal free download now.

author: Faringdon
author_rank: Super Contributor
timestamp: June 23, 2021, 07:08:33 pm
content: Thanks, ive searched the web and it looks like you cant even buy PADs standard any more?
FOSS for PCB trace/plane resistance analysis - Page 1
Forum section: electronics / general

author: Palmitoxico
author_rank: Regular Contributor
timestamp: June 14, 2021, 08:19:34 pm
content: Does anyone knows some free / open source software solution that does this:https://manual.pcb-investigator.com/pages/trace_resistance_simulation_ohmmeter? I have a complex multilayer PCB with GND planes / pours and need to do some resistance checking between different points before manufacturing, this type of simulation doesn't seems to be commonly included into most PCB EDA packages.Maybe there is some Finite Element Analysis library that can do this kind of thing with some extra coding, but I'm not very familiar with those. If anyone can provide some pointers where to start I would be glad!ThanksAugusto.

author: Pseudobyte
author_rank: Frequent Contributor
timestamp: June 21, 2021, 05:58:13 pm
content: If you were determined enough you could download GNU octave and setup the gerber interpreter and ODE system yourself. Otherwise FreeFEM might be a fairly similar avenue that is more geared towards FEA but still requires you to know some math/physics.

author: pointhi
author_rank: Contributor
timestamp: June 21, 2021, 06:15:02 pm
content: If you are adventurous, there is a WIP integration of power and signal integrity for KiCad:https://gitlab.com/pointhi/kicad/-/tree/sparselizard_fem(Old) build instructions:https://gitlab.com/pointhi/kicad/-/wikis/Sparselizard-branch

author: Palmitoxico
author_rank: Regular Contributor
timestamp: June 21, 2021, 07:45:40 pm
content: Quote from: pointhi on June 21, 2021, 06:15:02 pmIt looks promising, I'll take a look.Quote from: Pseudobyte on June 21, 2021, 05:58:13 pmI was going to this path, but I quickly discovered how little I know about FEA in general.
Any good youtube videos for Mentor PADs Logic and Pads Layout (standard Ed) - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: June 21, 2021, 04:44:48 pm
content: Hi,I have looked at a lot of tutorial videos for Mentor PADs but they are mostly poor and long-winded.Please do you know of any good concise ones?
LTpowerCAD wont allow selection of ADP2303-5  Buck controller? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: June 20, 2021, 06:49:09 pm
content: Hi,We are trying to set up LTpowerCAD with a ADP2303-5 based buck converter for 12V to 5V and 0.5A output.We want to use an inductor of 6.8uH, and an output capacitor of 56uF, Aluminium poly.However, the LTpower CAD program wont allow this, it keeps selecting a different controller which we don’t want. The program also runs very slowly, ( but this might be because i only have 4MB of RAM in my laptop?)Do you know how to do this?
Software that can rasterize RS274 files - Page 1
Forum section: electronics / general

author: ace1903
author_rank: Regular Contributor
timestamp: June 23, 2021, 03:59:48 pm
content: I am experimenting with PCB etching at home. I need tool that can rasterize gerber files to bitmap picture with predefined resolution.I downloaded several gerber viewers and tried to export layers but none of them has option to set resolution.GBR_RIP from artworks advertises such feature but it is 3500$.Does any of you knows such a tool that has hobbyist friendly price?

author: ace1903
author_rank: Regular Contributor
timestamp: June 24, 2021, 01:19:36 pm
content: Actually gerbv has some potential. When I first tried I missed field to enter DPI for the resulting PNG image.Today I tried it carefully and noticed DPI field in export dialog.Seems that PNG can be parsed in python or other programming language to produce different picture formats.
Free screen recorder for Teams tutorials on PADS - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: June 22, 2021, 04:58:33 pm
content: Hi,Do you know of any safe to download, free screen recorders for use recording Teams tutorials on PADs?Or if none free, which is the best value for money and safe to buy?I have bandicam, but its only for 10mins recording. Also Debut, but its also similarly limited.

author: PlainName
author_rank: Super Contributor
timestamp: June 22, 2021, 05:59:50 pm
content: Would OBS Studio be suitable?https://obsproject.com/

author: Faringdon
author_rank: Super Contributor
timestamp: June 27, 2021, 03:08:52 pm
content: Thanks, i ended up using zoom, and setting up a meeting with myself, then clicking "share" and also clicking "share audio".I play it back with VLC media, because then i can speed up to get through the not needed bits.Its a nuisance in VLC media to speed though up because theres no shortcut key for it.

author: PlainName
author_rank: Super Contributor
timestamp: June 27, 2021, 03:20:38 pm
content: Great bit of lateral thinking

author: Mark
author_rank: Frequent Contributor
timestamp: July 02, 2021, 10:05:23 am
content: Quote from: Faringdon on June 27, 2021, 03:08:52 pmIn VLC, use the square bracket keys:] for 10% faster] for slower.

author: mariush
author_rank: Super Contributor
timestamp: July 02, 2021, 10:10:50 am
content: Virtualdub can also do screen capture and audio capture :https://sourceforge.net/projects/vdfiltermod/Not as friendly UI as OBS but straight out the box has potential to produce higher quality capture as you can use lossless codecs for the initial capture, like MagicYUV for example.You can tweak the x264 settins in OBS for near lossless by entering command line parameters ex --qp 5 --tune stillimage for example but you still get a lossy mp4/mkv fileThere's a capture menu, you have to set the destination file , them set capture source , codec to compress with, then select audio source, codec to compress audio with (can leave uncompressed audio but will use space) and then you can capture to your heart's desire.
Looking for purchase ESD brush set for cleaning PCB and other electronic gears ? - Page 1
Forum section: electronics / general

author: zillah
author_rank: Contributor
timestamp: January 15, 2019, 09:32:04 am
content: Dear ExpertsI am a tech and I will be using them everyday , ,,,,looking to buy a quality set of anti static cleaning brushes something similar to the below link and there many others sources (but not sure of quality):https://www.ebay.com/p/8pcs-ESD-SMD-Specialized-Anti-static-Cleaning-Brush-Set-for-Repair-PCB-Soldering/686658829I found one brand OXO but not as sethttps://www.amazon.com.au/OXO-Good-Grips-Electronics-Cleaning/dp/B0050B6CYWCan you please advise where can I get them ? If there is no set I don't mind to buy individual quality one and make a set for myselfNo objection to spend little bit since i will be using it for workThanks

author: nsrmagazin
author_rank: Regular Contributor
timestamp: January 15, 2019, 01:45:08 pm
content: The best ones I found(in the site they found it for me, after sending them an email):http://www.cfcbazar.com/products/black-non-slip-handle-pcb-rework-esd-anti-static-dust-brush-17cm-for-mobile-phone-tablet-pcb-bga-repair-soldering/

author: zillah
author_rank: Contributor
timestamp: January 15, 2019, 01:49:14 pm
content: Thanks for the sharing

author: zillah
author_rank: Contributor
timestamp: January 19, 2019, 04:02:48 am
content: What i did ,,,I changed my Google search phrase to be : "Conductive Brushes" and all below from reputed websiteshttps://au.rs-online.com/web/c/safety-security-esd-control-clean-room/esd-control-clean-room/esd-safe-brushes/https://www.all-spec.com/Search?categoryId=658a6bb4-ed5f-4dee-a68e-a5b20032acd6&filters=&sortby=8&page=1&pageSize=16&criteria=brush&view=list&columns=https://precisionbrush.com/anti-static-brusheshttps://au.element14.com/c/static-control-site-safety-clean-room-products/esd-protection-products/anti-static-brushes

author: nsrmagazin
author_rank: Regular Contributor
timestamp: January 19, 2019, 08:59:29 am
content: Its country dependent, but they probably buy them from China too.

author: zillah
author_rank: Contributor
timestamp: January 19, 2019, 09:13:58 am
content: Remember most of things (not all) manufactured in China ,,,,Your iPhone manufactured in China but under certain conditions.For me (may be not everyone) there are good quality chinse products and bad quality ,,,,but when I buy from an authorised dealer I can trust that Chinese product (for example buying iPhone from an Apple dealer)Element14 (28 countries) and RS Component (huge list of countries)http://grh.premierfarnell.com/pageredir.aspx?c=EU1&u=jsp/search/displayproduct.jsp?SKU=2357308%26CMP=SOM-TW-e14-OM-Raspberrypi-noirhttp://www.rs-online.com/

author: Liukerry
author_rank: Newbie
timestamp: May 21, 2021, 07:20:10 am
content: I think this is ok.http://www.aoqunbrush.com/nylon-rotary-cleaning-pumice-brush-for-printed-circuit-board-pcb_p69.htmlhttp://www.aoqunbrush.com/
Logisim Evolution - Page 1
Forum section: electronics / general

author: djsb
author_rank: Super Contributor
timestamp: May 15, 2021, 03:16:16 pm
content: Just thought I'd share my discovery of this open source logic simulation software. It's a further development of the original Logisim.https://github.com/reds-heig/logisim-evolutionThere is a short video here that first made me aware of this software.There are a few more on YouTube.

author: nctnico
author_rank: Super Contributor
timestamp: May 17, 2021, 02:23:40 pm
content: This is interesting. Especially since it supports VHDL. It could be a useful tool to create quick testbenches to test pieces of VHDL code. I might give this a try; I have an upcoming VHDL project.

author: Bassman59
author_rank: Super Contributor
timestamp: May 18, 2021, 03:08:28 pm
content: Quote from: nctnico on May 17, 2021, 02:23:40 pmMy test benches use bus-functional models of the devices that connect to the FPGA design. I don't know how well that would work in this environment.

author: rdtsc
author_rank: Newbie
timestamp: May 18, 2021, 11:40:39 pm
content: I'm a little leery of installing this on Windows. Unsure about the other versions and OS's, but some rather unusual things appear to be going on in the latest v3.4.5 for Windows:https://www.virustotal.com/gui/file/4cfb842f402e5acdc424780f3e7faa112841517002a3cc24bcefd208c36bac31/detectionHopefully someone can come along with evidence that this behavior is truly benign.

author: dave_k
author_rank: Frequent Contributor
timestamp: May 19, 2021, 12:16:26 pm
content: "No security vendors flagged this file as malicious."

author: rdtsc
author_rank: Newbie
timestamp: May 20, 2021, 01:37:41 pm
content: Right, I think the code itself is fine. Just some peculiarities about the installer are triggering suspicion.Why is msiexec.exe started in 'C:\Users\admin\Downloads\msiexec.exe'?Why are files written to 'C:\Windows\ServiceProfiles\LocalService\AppData\Roaming\Microsoft\UPnP Device Host\upnphost\udhisapi.dll' and 'C:\Windows\System32\Tasks\Microsoft\Windows\DiskDiagnostic\Microsoft-Windows-DiskDiagnosticDataCollector'?Why is the registry key 'HKLM\SOFTWARE\Microsoft\Windows Media Player NSS\3.0\Servers\A70D59A1-8EAD-4F40-AAAB-FBFC460800A4\FriendlyName' set to 'WORK:admin'?In any case, I was able to extract the .msi usinghttps://www.legroom.net/software/uniextract#download(7zip would not work) and THAT all tests fine, nothing suspicious. Runs fine, too. It does cause a Windows Firewall message to popup, asking for access to your network/domain. Can un-check and click Cancel.
Source for PCB and partial assembly - Page 1
Forum section: electronics / general

author: mawyatt
author_rank: Super Contributor
timestamp: June 03, 2021, 04:55:36 pm
content: Have a project that needs to get a PCB fabbed and partially assembled. The PCB will be a usual 4 layer about 6" square, and one design will use a AD5535B which is a 124 pin BGA, and the other will use a AD5380 which is a 100 pin LQFP. We can't mount these parts and will need to have them mounted, the rest of the boards can be assembled here at the labs.Normally we use EasyEDA & JLCPCB, but the footprint is not available for the AD5535B in EasyEDA format (I believe since I couldn't find it), and JLCPCB doesn't handle assemble of either the AD5535B or AD5380. The other PCBS for the project will be the usual JLCPCB which we assemble ourselves.Any recommendations/help are appreciated.Best,

author: Evan.Cornell
author_rank: Regular Contributor
timestamp: June 03, 2021, 08:38:26 pm
content: Check out MacroFab.com.
OrCAD Refdes on hierarchal pages - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: May 04, 2021, 03:59:29 pm
content: I'm trying to update a few components on a hierarchal page. However, when I name the part that part number is replicated on all occurances for that page. So I end up with four U59 parts. How do I get the part number to be automatic? I tried using the annotate feature but it ended up renaming all the components in the project.Any advice?

author: Uky
author_rank: Regular Contributor
timestamp: May 04, 2021, 04:25:50 pm
content: Have you tried pushing occurancies into instances? (Getting rid of the "yellow" lines in the property tables).I have not personally used ocurrances in hierarchical designs, but rather used annotation prefixes based on page numbers.

author: Pack34
author_rank: Frequent Contributor
timestamp: May 04, 2021, 05:38:48 pm
content: Quote from: Uky on May 04, 2021, 04:25:50 pmHow do you do that? I see the yellow lines on the property editor

author: Neilm
author_rank: Super Contributor
timestamp: May 04, 2021, 06:42:08 pm
content: You may have to reannotate with the annotation set correctly.

author: nctnico
author_rank: Super Contributor
timestamp: May 04, 2021, 06:48:36 pm
content: I strongly suggest to read the manual in this case c.q. follow a tutorial. There are some specifics to setting up hierarchial schematics in Orcad. Simply annotating is not going to help.
How on EARTH do you lay out a part like this? - Page 1
Forum section: electronics / general

author: alexwhittemore
author_rank: Frequent Contributor
timestamp: January 20, 2021, 02:24:57 am
content: A new client came to me today with a debugging problem they're frantically trying to solve. Long story short, I'm pretty sure the whole issue is how they've laid out USB 3.0 pairs with big 1" stubs running off to a TVS diode, times six for the connector.Which leads me to the question, because I've seen this a LOT: TheWurth 82401646comes in an MSOP-8 package, just WILDLY ill suited to coherently routing differential pairs near/past it so as to keep stub length minimized and avoid vias. Like, I can't imagine there's a way to do it for USB3.0 without stubs/vias and while maintaining any SEMBLANCE of impedance control. And yet, that datasheet specifically calls out "high speed differential signals like USB3.0".Why do these kinds of parts exist? Who uses them, besides people who quickly learn not to? Why does this part tell me it's for USB3.0 when it's virtually guaranteed to tank a USB3 design?Like, what am I missing here?

author: fourfathom
author_rank: Super Contributor
timestamp: January 20, 2021, 03:22:38 am
content: Like this? There's some coupling between 1/2 and 3/4, but perhaps not too bad. Or don't I get it? (it happens)

author: alexwhittemore
author_rank: Frequent Contributor
timestamp: January 20, 2021, 03:29:00 am
content: No - I think you're right. That's the solution a friend just came up with as well. Two of those pairs DO get perilously close. And it's a tight squeeze unless you're working with roughly 3mil prepreg by my estimate (I assumed you wouldn't be able to fit 4 traces underneath at controlled impedance sizing, but maybe). But that might actually be a practical way to do it.That said, I think I'll probably design in purpose-built fly-by parts still

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 02, 2021, 06:56:17 pm
content: I would also use two via's for GND and Vcc each. One via north, and the other south of pads 7 & 8, and I would add a decoupling capacitor. This capacitor will (partly) short circuit transients, instead of shunting them into your power planes.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 02, 2021, 07:15:28 pm
content: Weird, they show a diode from VCC into the TVS. Well, if that's the case, it's just for bias, and clamping itself, not for bypass. So, uh, that saves vias, then, huh?...Tim

author: nctnico
author_rank: Super Contributor
timestamp: May 02, 2021, 08:16:07 pm
content: Quote from: Doctorandus_P on May 02, 2021, 06:56:17 pmA better way is to put a series resistor between power and VDD. Don't feed transients into your power rail!

author: free_electron
author_rank: Super Contributor
timestamp: May 03, 2021, 06:49:37 pm
content: Quote from: nctnico on May 02, 2021, 08:16:07 pmcorrect, and do not forget to put a small capacitor across the tvs diode. That way the transient get shorted by the capacitor as well.
PCB cad software in the far east - Page 1
Forum section: electronics / general

author: free_electron
author_rank: Super Contributor
timestamp: May 03, 2021, 06:45:21 pm
content: what software is in use over there ?The reason for asking : if you look at crcuit boards commonly made by Sony, Harman-kardon, Onkyo, Clarion , as used in TV , refrigerator, microwaves and other household , audio/video ( i am not talking complex boards like fro tablets and smartphones ).These boards are often single-sided ,use wire straps as 'bridges' , and they all have a very unique (read 'different') look from your traditional board layout tools like altium / cadence / mentor.The fonts are unique , the routing style is different , there is (or was) often complex silkscreen ont he solder side showing parts symbols, designators.Even their schematic drawing style is totally different from what we are used to. look in service manuals from Technics, Marantz , onkyo .. that is a very special style.Certain boards are 'breakable'. after running through the wave soldering machine the board is broken and installed in the chassis. during wave soldering wire harnesses are soldered in one show so when you break the board it is already connected.The schematic drawings reflect that. Netnames on broken pieces remain the same , so somehow these tools are capable of understanding that the net travels through an-off board wire and do not throw a fit of having a broken net.The same thing is also true for the wire straps. the tool is capable of shooting these in the pcb without having to alter the schematic. it need sto follow rules pertaining to the length of such a strap as the machine that stitches them needs presets. and the pick and place file need to have their coordinates.So this kind of layout software has abilities we are not used to in traditional pcb cad software.I am curious to know what software that is.Do we have anyone on here that uses , or knows someone that uses, PCB software at those companies ?I foudn a couple of 'homegrown japanese market' toolsZuken CR8000Zuken Cr5000QuadceptYokogawa Cadvance Alpha-III ( end of life end of 2020 -> bought out by zuken and killed off)Sohwa-SophiaUnicraft OPUSERThis one does teardropping on the fly. also the interactive router has unique skills like equidistant breakout . They have lots of demo videos. ( you can click the little circles under the video to see various demos.CADLUS Onewww.cadlus.comhttps://www.cadlus.com/products/cadlusone/demo/This one looks very interesting as it can do codesign of asic, substrates, wirebond, chip on board and board and trace the nets through all the elements.FIRSThttp://www.first-cad.com/products1/products1_top__en.html
How do I model a custom LED with TINA? - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: April 28, 2021, 09:50:26 am
content: I am usingDesignSoft TINA v8to simulate a couple of circuits. Everything is fine, except its library only supports a few models for the LED component and none of these models looks fine because with 5V I need a low Current-Limiting Resistor to turn the LED on.LEDs are constant current devices with a predictable forward voltage drop based on the amount of current flowing through them. These I-V current-voltage curves are available in the datasheet for specific LEDs. The CQX35 shows it nicely, so if you want to drive one of these LEDs with a forward voltage of 1.5V off a 5V power supply, you need something in that circuit to absorb the extra (5-1.5)V. The easiest way to absorb extra power in a circuit is to use a simple resistor. You need to know the intended LED to define the resistor using V=IR, but the math is very straightforward once you determine your system parameters. If you want to drive that 1.5V LED at 5mA, you need to absorb (5-1.5)V at 5mA in a resistor. (5-1.5)V = 5mA * R. Solving for R gives a resistor value of 700 ohm.700 ohm looks ok, but it's definitively too small far from what I'd like to achieve with my simulations, since I would like to have 1K ohm, so I would like to model a different LED.Unfortunately I can edit the properties of the component, but I am bit lost with too many parametersCode:# Name Parameter Units Default Example Area1 IS Saturation current A 1e-14 1e-14 *2 RS Ohmic resistance Ω 0 10 *3 N Emission coefficient - 1 1.04 TT Transit-time s 0 0.1ns5 CJO Zero-bias junction capacitance F 0 2pF *6 VJ Junction potential V 1 0.67 M Grading coefficient - 0.5 0.58 EG Activation energy eV 1.11 1.11 Si0.69 Sbd0.67 Ge9 XTI Saturation-current temperature exponent 3.0 3.0 jn2.0 Sbd10 KF Flicker noise coefficient - 011 AF Flicker noise exponent - 112 FC Coeff. for for.-bias dep. cap. formula 0.513 BV Reverse breakdown voltage V ∞ 40.014 IBV Current at breakdown voltage A 1.0e-315 TNOM Parameter measurement temp. °CI was expecting to find just two parameters: "If" and "Vf". There many more.I haven't yet understood how to import a PSPICE model into TINA, I am not sure I can do it with version 8, I haven't enough budget to upgrade to v12.Anyone has already tried to create a custom LED model for TINA? If so, let me know
Ground Plane connection missing in Protel 99SE - Page 1
Forum section: electronics / general

author: jcdammeyer
author_rank: Newbie
timestamp: April 28, 2021, 12:57:47 am
content: I was making some changes to a PCB and went back to 99SE from Altium with a save as 4.0 version. Anyway, the original board had cross hairs on the vias and pads that intersect the ground plane net while the new one is missing the cross hairs on the pads and shows the nets as not routed. The attached screen shots show what I mean.What needs to be done to reconnect the GND and VCC planes?

author: jcdammeyer
author_rank: Newbie
timestamp: April 28, 2021, 02:46:41 am
content: It appears the transition from Altium18 back to 99SE has created what 99SE calls Split Planes. Double click on the GND layer that surrounds a pad and you get a choice to edit the pad or one of the two split planes VCC and GND. Then the Split Plane (GND) can be selected and "Connect To NET" in the dialog assigned to GND. Same with VCC.That now shows the correct connection to the plane and also the gerbers for .GP1 and .GP2 show the appropriate connections.As yet I've not figured out how to remove these "Split Planes". Altium18 help says a plane can be split by drawing a line on it but I can't find how to undo that.Also as the screen shot of a section of the gerber shows, the border around the plane is wide. About 5x as wide as a gerber from the previous 2016 version.

author: jcdammeyer
author_rank: Newbie
timestamp: April 28, 2021, 03:14:44 am
content: More progress after studying the Protel 99SE help files. The docs explain how to create a split plane but not how to remove it. Turns out pretty simple.1. Turn on only the minimal layers like Keepout or Mechanical, the multi-layer and the ground plane.2. Click on the tab for ground plane. In my case it's green3. Under Edit | Select | All on Layer and then click inside the ground plane outline. A thin border around the board in the same place as the keep out lines shows up as selected.4. Delete this.5. Do the same for the VCC plane.6. Show used layers again.Now the split plane properties no longer show up with a double click on ground plane tab.As yet I have not figured out how to create the smaller border on the GND and VCC internal planes.Probably not important unless the board fabricator decides to use it as the board size. Be nicer to have it match the keep out dimensions.If I find out I'll post a solution. Otherwise hopefully I've documented well enough not only the problem but also the solution.
converting old .PCB file - Page 1
Forum section: electronics / general

author: zoinknoise
author_rank: Newbie
timestamp: April 21, 2021, 11:37:06 pm
content: hi folks, i come seeking help. i've got a PCB design here (released freely) that was made in 1998 with Protel for DOS. i am struggling to get it converted to modern Gerber files so i can have some boards made for myself. i've played around with Protel SE 99 but i can't get the drills exported properly. AGH!! can anyone help?file attached.

author: zoinknoise
author_rank: Newbie
timestamp: April 22, 2021, 12:22:53 am
content: was planning to add solder mask and export Gerbers.

author: E-Design
author_rank: Regular Contributor
timestamp: April 22, 2021, 12:31:40 am
content: It imports but the hole sizes are zero. with some time, could be manually fixed since most look to be the same size. I set them to .05 inch so they could export.attached is the drill file you requested. this should import into your tool and you can fix them.

author: zoinknoise
author_rank: Newbie
timestamp: April 22, 2021, 12:32:59 am
content: thank you kindly
RAM/ROM Simulation with Microcap? - Page 1
Forum section: electronics / general

author: marcopolo
author_rank: Regular Contributor
timestamp: February 23, 2021, 11:04:17 am
content: Hello,Do you know if it's possible with Micro-Cap to simulate RAM and ROM with an init file?Thanks,Marc

author: oliviasmithh900
author_rank: Contributor
timestamp: March 04, 2021, 12:36:04 am
content: RAM may be but ROM no chance ...

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 08, 2021, 02:21:42 am
content: I haven't seen any way of simulating a RAM or ROM with Microcap, so let alone specifying an init content for them. Haven't found a corresponding digital part or primitive.You may be able to design memory blocks using the digital primitives, although I expect this to be pretty tedious. See the reference manual for more info on digital primitives.What would you want to simulate RAM or ROM for?

author: marcopolo
author_rank: Regular Contributor
timestamp: March 08, 2021, 07:52:02 am
content: I would like to simulate a TTL microcoded cpu with 74181 and 74182

author: DiTBho
author_rank: Super Contributor
timestamp: March 08, 2021, 01:23:38 pm
content: I would write a RTL model and simulate it

author: marcopolo
author_rank: Regular Contributor
timestamp: March 08, 2021, 02:48:17 pm
content: Yes, but the next step is the build of the simulated computer with TTL IC.It's easier to start from an simulated schematic than to convert Verilog code to schematic even if I use TTL models in Verilog.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 08, 2021, 06:02:02 pm
content: I see. As I said, no RAM or ROM to be found in Microcap, so your only bet would be to implement static memory, for instance using flip-flop primitives. You'll need to know how to design subcircuits, how to use digital primitives... and then, flip-flops can get an initial value, but managing to initialize your custom memory subcircuits from a file, yeah... maybe using "file stimulus" to preload your memory cells during the initial phase of the simulation?Now maybe someone more expert with Microcap has a better idea.

author: marcopolo
author_rank: Regular Contributor
timestamp: March 08, 2021, 07:42:11 pm
content: The RAM problem can be solved with 74ls670 but not the ROM problem.I'll look for another software for this project, maybe an old ALTERA Quartus in schematic mode with its library of TTL circuits.If anyone has any ideas, they are welcome

author: marcopolo
author_rank: Regular Contributor
timestamp: April 19, 2021, 01:38:27 pm
content: This software can simulate TTL IC, RAM and ROM:https://github.com/hneemann/Digital
layout help based on trinamic's TMC4671 - Page 1
Forum section: electronics / general

author: tido
author_rank: Newbie
timestamp: May 12, 2021, 09:45:09 am
content: This is my first high power PCB board. I have been doing some reading and going through few reference designs. really looking for some guidance from the community .please do correct me and if possible point me at the right direction.Lot of people has suggested for 70um or 2ounce copper. i personally want to avoid it if possible and use any existing PCB Stackup from JLC PCB 4 layer stackup with standard FR-4.Also My stack up plan is to keep [1.SIG TOP | 2. GND | 3. POWER | 4. SIG BOT].The Layout keeping the digital and analog grounds on the same ground plane with decent separation.The board has to drive a 3 phase BLDC motor.1. I was planning on keeping control Board(TMC 4671) and the gate driver with Power MOSFET on a separate board connected using a board to board connector.Q> should i do it on single board?2. Usually design guides recommend lots of Vias while routing in between planes. for the Power MOSFET.Q> should i do it on single board? what is lot and how can i calculate it.?3. I am using Vias with 0.45mm diameter and 1.6mm height.Q> I am not sure what should be the height so i assume board thickness from top layer to bottom here is it correct?Q> Should i use thermal relief Vias for the MOSFET? if yes, how can i use and also where to decide to put thermal relief vias.?4. Planning for a 2mm trace with standard FR4 dielectric. And minimum conductor space of 0.6-0.8mm.Q> should i do it on single board ? Is the Conductor spacing and trace enough since 100A(Assuming less than 5A continuous)?PS: Attaching images for reference of Saturn PCB toolkit also ask any other parameters i will try my best to answer. Still lot to learn.thank you.

author: Pseudobyte
author_rank: Frequent Contributor
timestamp: May 13, 2021, 04:45:31 pm
content: Trinamic makes their evaluation board designs available for free. That is probably a great place to start.
Design Review for a charging/boost converter/Li-ion protection board - Page 1
Forum section: electronics / general

author: bwmms
author_rank: Newbie
timestamp: April 02, 2021, 09:36:50 pm
content: Here is an album of images from Altium including schematics. Schematics have details on current and voltage requirements. Any advice is appreciated, thank you!https://drive.google.com/drive/folders/1wePywaqI2jC3yr0VGdTNUM-Ny12sh8vM?usp=sharing
Simple schematic from nodes file? - Page 1
Forum section: electronics / general

author: aneng
author_rank: Regular Contributor
timestamp: April 26, 2021, 05:53:12 pm
content: Hi. I'm very much a noob to component level repair and I find it difficult to visualise the connections just by looking at a PCB. I've learned about nodes and wondered if there was an easy way of generating a simple schematic from a nodes file. I can look at a PCB and create a text file of nodes quite easily - it's turning that into something that looks like a schematic that's the issue.If not this way, how else do you create a schematic from a simple PCB please?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: April 27, 2021, 08:14:56 pm
content: This is a nice tutorial of reverse-engineering a PCB with KiCad:https://learn-cnc.com/reverse-engineering-pcbs/Or a more generic search, which also brigs up instructables and other resources:https://html.duckduckgo.com/html?q=kicad+pcb+reverse+engineerI can see two changes that would be very useful for reverse engineering a PCB, and I'm hoping they will someday be included in KiCad.The first is to have a .jpg image as a background. It should be scalable, and preferable also some simple editing corrections such as reversing parallax and barrel distortion. But making a picture perpendicular from the PCB and from a long distance and using the zoom of your camera is usually good enough, and using a flatbed scanner is also an option of course.The other tool would be a ratsnest in the schematic drawing program.Normally in a PCB design suite you first draw a schematic, then put all footprints "random" on a PCB and you sort them out by using the ratsnest lines and other tools.This can also be made to work the other way around. You place footprints on the PCB on the locations given by the photograph, and you re-trace the copper tracks. This combination creates a netlist. Then you attach schematic symbols to the IC package footprints, and you have all the information to draw ratsnest lines in the schematic.I am not aware of an EDA suite that can do this all though.Lots of reverse-enginurding tutorials use generic photo editing programs in their workflow.

author: PlainName
author_rank: Super Contributor
timestamp: April 28, 2021, 08:56:32 pm
content: QuoteNeat idea. I reckon I'd find a use for that even doing forward engineering
Can anyone recommend a good mousebite drill pattern that breaks cleanly? - Page 1
Forum section: electronics / general

author: deanclaxton
author_rank: Regular Contributor
timestamp: April 01, 2021, 08:59:37 am
content: I use JLCPCB for my boards generally, and use a fairly generous 2mm routing slot width and 6mm tab (4mm at narrowest point). I'm interested in drill patterns for the tab which break away cleanly - recommended drill size and spacing, board edge to drill centre distance etc. Most of the patterns I've used to date leave "fingers" of FR4 sticking out past the board edge between the holes which leads me to think that I'd be better off going smaller on the drills and having more of them.The latest pattern I used was 5 x 0.75mm holes spaced at 1.27mm centres and set back 0.25mm from the board edge. The routing path intersected the holes at each end ( I was trying to ensure the snapped edge was back inside the board outline). See the attached file for the layout I am describing.Very interested in patterns that people have had good clean easy breaking boards with.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: April 01, 2021, 02:45:29 pm
content: Depends on board thickness and material and how many mousebites you have in a line. Easiest is to simply let the assembly house tell you what they think is best and use that.

author: Algoma
author_rank: Frequent Contributor
timestamp: April 01, 2021, 03:29:53 pm
content: Few pattern notes here, if of any use:https://www.electronicdesign.com/technologies/boards/article/21801451/pcb-designers-need-to-know-these-panelization-guidelinesCleanest Edge would be a straight V-Groove but requires a bit more effort to separate the panels.https://www.allpcb.com/mouse_bites_pcb.html

author: deanclaxton
author_rank: Regular Contributor
timestamp: April 01, 2021, 11:20:13 pm
content: Thanks - yeah the catch there is that I'm rounding the corners on the boards which makes v-score a bit tricky. Will definitely give that more thought though. Also on one design there are traces going across the bridge - so I need a tab for that one.That's a good link - pretty sure I used those guideline originally. I might try smaller drills and more of them with tighter spacing.Actually there is a recommendation in there "Ideally with outside edge of holes in line with edge of board - cleanerbreak" where the hole is tangent to the board edge - might give that a go. That would mean moving the drill centre line back inside the board slightly in my case.

author: beanflying
author_rank: Super Contributor
timestamp: April 02, 2021, 12:44:21 am
content: While this will still likely need a wipe with something for the sharp edge (deburring tool) post breaking out any reason not to consider this style. I use this on timber boards when routing out panels (manually) and last time I fired up my baby router to do a PCB it was the 'normal' toolpath. It is also the more normal panel method with larger CNC routers as it avoids a bit change.Last boards I got from OSHPark needed a fair bit of work to fix their mousebite pattern.
STMPE811 Part Search - Page 1
Forum section: electronics / general

author: Matt95
author_rank: Newbie
timestamp: March 31, 2021, 02:47:04 pm
content: Need support on the availability of a particular component; is it possible to have some more info on the possible availability STMPE811 component? Unfortunately, they are currently not available in any distributor. But it could be that some customers have them in stock to lend us, 1000 pcs would be enough.

author: ataradov
author_rank: Super Contributor
timestamp: March 31, 2021, 03:21:17 pm
content: Please don't post the same stuff in multiple places.
Best storage of pasted PCBs for assembly over a week - Page 1
Forum section: electronics / general

author: Psi
author_rank: Super Contributor
timestamp: March 05, 2021, 01:27:07 am
content: I need to do a big hand assemble PCB build (SMT+reflow) and I really want to do them all at once instead of in small batches. ie, paste them all, then go through placing each part on all boards.But this will take a 3-4 days due to available time each day and I'm not sure how to best store a PCB that has already been pasted and is part way through assembly?I do have a spare/empty fridge that I could use?Anyone know if that is going to be fine?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: March 27, 2021, 10:39:54 pm
content: You could try your fridge, but I do not give you much of a chance.Once applied, solder paste is usually good for only half an hour up to maybe a few hours, but not days.

author: wraper
author_rank: Unknown
timestamp: March 27, 2021, 10:54:30 pm
content: I do not suggest fridge. Your boards will become moist once you take them out and paste likely will absorb some of that moisture. You can use GC-10 solder paste as it's temperature stable and dries out the least AFAIK. It will more or less last for 4 days, however it's pushing it. Do not recommend more than 2 days.
Yet another Eagle to KiCad converter - Page 1
Forum section: electronics / general

author: Karel
author_rank: Super Contributor
timestamp: March 23, 2021, 08:52:43 am
content: This is a standalone program that converts a Cadsoft Eagle V7 & V6 library to a KiCad equivalent (*.dcm, *.lib, *.kicad_mod),symbols and footprints, including the attributes.Thought it could be useful for people that want to make the switch.https://gitlab.com/Teuniz/eagle2kicad
JLC shopping cart problems - Page 1
Forum section: electronics / general

author: fastguido
author_rank: Regular Contributor
timestamp: March 26, 2021, 06:06:14 pm
content: Has anyone had problems with viewing their shopping cart or checking out lately? I have four designs/items in the cart but won't let me view the cart or check out, just spinning wheel when I click on it. I emailed them, but no response yet.

author: thm_w
author_rank: Super Contributor
timestamp: March 26, 2021, 09:04:08 pm
content: Have you tried turning it off and on again?Seems ok here. You could always make a second account if you've tried all the basic steps already.
Microcap 12 Probing pin current of subcircuit. - Page 1
Forum section: electronics / general

author: kashinath
author_rank: Newbie
timestamp: March 07, 2021, 09:34:59 am
content: In MC12 Probe cannot directly plot current into a macro or subcircuit pin. What I do is add a small resistor in series with the pin then plot the current through resistor. Is there some better way of doing this ?