Many errors on DRC check for Schematic KiCad - Page 1
Forum section: electronics / beginners

author: redgear
author_rank: Frequent Contributor
timestamp: November 22, 2019, 05:10:22 am
content: I just completed a schematic and when I run the DRC, I get many errors. All the errors are either Pins not being driven or conflict problem between pins. I made a custom symbol for a part and I should have messed up while assigning the type of pins which is causing the conflict errors. I assume I can ignore them. What is with the pins not being driven? I checked all connections and they are properly connected.I'm attaching my schematic and the error log. Can anyone help me with it?Thanks

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: November 22, 2019, 06:03:34 am
content: QuotePlace a PWR_FLAG on the VBUSC net. Ditto for pin 2 of U1. Also the other VBUSes.QuotePin 27 (and 28) are not power outputs. They are just current sense leads. Mark them input or passive.QuoteSame here. These also should be connected to your power bus. Leave a reminder for yourself with the text tool if you care to Kelvin-connect them during layout, but I'm not sure it matters a whole lot if you make your VOUT traces nice and wide. I've never seen that chip before and can't find data, so I can't be sure. Have you given up on the IP5328, then?You shouldn't put more than one label on a single net (VOUTA, VOUTC, etc.) or the extras might get pruned on the way to layout.QuoteSW pins are bidirectional, for both charging and discharging. Adjust your symbol accordingly.You can assign just one pin to a signal, instead of multiple shield pins. In the footprint, you can then assign that same pin number/name to multiple pads, which will all be connected to the net or no-connect, as appropriate.

author: redgear
author_rank: Frequent Contributor
timestamp: November 22, 2019, 09:14:01 am
content: Quote from: jhpadjustable on November 22, 2019, 06:03:34 amWhen I was mid-way building the PCB with IP5328, I found this IC with better features so I started redoing the whole design with this IC. This a SW6208 from ismartware. I will attach the datasheet below.QuoteOk, will remove them.QuoteThe shield pins are getting connected to the ground. Can I use the same pin number as GND for the pads and remove the shield pins from symbol?Thanks

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: November 22, 2019, 09:45:37 am
content: Quote from: redgear on November 22, 2019, 09:14:01 amWhere?QuoteBad idea. Shield should be tied to ground only at the upstream e- oh, wait, that's you.I still advise against combining them in the symbol, since the pins serve very distinct functions and you want to avoid passing current through the shield. Any noise on it will then be radiated instead of contained inside the cable. You should connect the others to ground, but you'd definitely want to leave the charging port facing upstream (J3?) non-connected. (EMC greybeards can please tell me if I'm full of it)

author: redgear
author_rank: Frequent Contributor
timestamp: November 22, 2019, 10:21:46 am
content: Quote from: jhpadjustable on November 22, 2019, 09:45:37 amOops. I forgot to attach it. I am attaching it with this reply.QuoteAlright. But the datasheet has the shield pins connected to GND on the J3 port.

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: November 23, 2019, 06:18:15 am
content: Neat chip! Too bad it seems relatively hard to source in single quantities. Maybe Li Chuang will pick them up before it goes EOL.Come to think of it, it could be argued that a power bank is a bus-powered hub, especially if it's designed for pass-thru powering, and therefore might benefit from pass-thru shielding. I'll have to punt to the EMC elders on this... anyone?

author: redgear
author_rank: Frequent Contributor
timestamp: November 25, 2019, 05:14:19 am
content: The schematic on the datasheet did not have a electrolytic cap on the VOUT pins but I just added one like in the IP5328. The capacitors were rated for 16v, I changed them to 25v. Am I being very conservative here? Should I remove the elcap?

author: redgear
author_rank: Frequent Contributor
timestamp: November 28, 2019, 07:43:40 am
content: Quote from: jhpadjustable on November 22, 2019, 06:03:34 amHave made the changes you suggested, still I have few errors.Code:***** Sheet /ErrType(3): Pin connected to other pins, but not driven by any pin@(124.46 mm, 81.28 mm): Pin 1 (Power input) of component #PWR013 is not driven (Net 4).ErrType(3): Pin connected to other pins, but not driven by any pin@(64.77 mm, 171.45 mm): Pin 3 (Power input) of component U1 is not driven (Net 15).ErrType(5): Conflict problem between pins. Severity: error@(82.55 mm, 101.60 mm): Pin 14 (Power output) of component U2 is connected to@(62.23 mm, 115.57 mm): pin 1 (Power output) of component #FLG0110 (net 30).ErrType(5): Conflict problem between pins. Severity: error@(62.23 mm, 115.57 mm): Pin 1 (Power output) of component #FLG0110 is connected to@(91.44 mm, 101.60 mm): pin 1 (Power output) of component #FLG0103 (net 30).ErrType(5): Conflict problem between pins. Severity: error@(91.44 mm, 101.60 mm): Pin 1 (Power output) of component #FLG0103 is connected to@(91.44 mm, 99.06 mm): pin 1 (Power output) of component #FLG0107 (net 30).ErrType(5): Conflict problem between pins. Severity: error@(91.44 mm, 99.06 mm): Pin 1 (Power output) of component #FLG0107 is connected to@(82.55 mm, 99.06 mm): pin 9 (Power output) of component U2 (net 30).ErrType(5): Conflict problem between pins. Severity: error@(82.55 mm, 99.06 mm): Pin 9 (Power output) of component U2 is connected to@(62.23 mm, 105.41 mm): pin 13 (Power output) of component U2 (net 30).ErrType(2): Pin not connected (use a “no connection” flag to suppress this error)@(53.34 mm, 76.20 mm): Pin 8 (Input) of component U2 is unconnected.ErrType(5): Conflict problem between pins. Severity: error@(82.55 mm, 48.26 mm): Pin 33 (Power output) of component U2 is connected to@(82.55 mm, 50.80 mm): pin 32 (Power output) of component U2 (net 54).ErrType(5): Conflict problem between pins. Severity: error@(82.55 mm, 50.80 mm): Pin 32 (Power output) of component U2 is connected to@(82.55 mm, 53.34 mm): pin 31 (Power output) of component U2 (net 54).ErrType(5): Conflict problem between pins. Severity: error@(82.55 mm, 53.34 mm): Pin 31 (Power output) of component U2 is connected to@(82.55 mm, 55.88 mm): pin 30 (Power output) of component U2 (net 54).ErrType(5): Conflict problem between pins. Severity: error@(82.55 mm, 55.88 mm): Pin 30 (Power output) of component U2 is connected to@(82.55 mm, 58.42 mm): pin 29 (Power output) of component U2 (net 54).

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: November 28, 2019, 11:15:27 am
content: Sorry I missed that earlier post. The datasheet design should work as published. No great harm in leaving the extra elcap footprint unless it's in the way or consuming badly needed space. You could stuff it later if you come to find it necessary, or not.If you've still got errors after this, can you upload a new copy of the sheet?Quote from: redgear on November 28, 2019, 07:43:40 amI'm guessing it doesn't see J2 as driving GNDPWR. Fair enough, add a PWR_FLAG.QuoteYour symbol is still broken. According to the datasheet p4, VOUTA*/C aren'toutputsfrom U2. Those are voltage sensinginputsconnected to the the big VOUT net, similar to VOUTSP. I suppose the idea is to use the MOSFET Rds(on) for current sensing of some sort. To keep the sense lines in order during layout, you could insert net tie symbols to divide the individual nets from the bus (at the 2s), and place the net tie footprints near the MOSFET drains.QuoteSounds like you now have multiple power flags on one net. Place only one.QuoteYou have no Lightning port. This one's a fair cop.QuoteAccording to the datasheet, VOUT pins are bidirectional (p4). One way to make the ERC error go away is to make the pins bidir in the symbol.In other cases, where you can't make them bidir, you can stack the pins in the symbol and the schematic editor should treat them as one. Seehttps://kicad-pcb.org/libraries/klc/section S4.3 for more info.

author: redgear
author_rank: Frequent Contributor
timestamp: November 28, 2019, 11:23:19 am
content: Quote from: jhpadjustable on November 28, 2019, 11:15:27 amNo problem, ThanksI looked at some designs and they don't use the elcap. While the circuit should work without it, I wanted to know if its worth the extra cost.QuoteOops, my bad. I copied pasted the entire thing.I will work on the changes and post the updated schematic. My laptop just crashed and strangely the entire schematic is blank after restart. I have saved it multiple times but idk how it is blank... I have to make it from it all over again.

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: November 28, 2019, 02:27:00 pm
content: There's a bummer.Perhaps you'll be lucky and there'll be a .bak file intact.

author: redgear
author_rank: Frequent Contributor
timestamp: November 29, 2019, 07:24:41 am
content: Quote from: jhpadjustable on November 28, 2019, 02:27:00 pmNope, I wasn't. I just finished redrawing the entire schematic. But this time I felt a little more comfortable and fast.Thanks a lot for your help. I followed your suggestions and now have only 2 warnings on the DRC.The errors are being inconsistent.Code:***** Sheet /ErrType(3): Pin connected to other pins, but not driven by any pin@(62.23 mm, 161.29 mm): Pin 2 (Power input) of component U1 is not driven (Net 16).ErrType(3): Pin connected to other pins, but not driven by any pin@(275.59 mm, 148.59 mm): Pin B12 (Power input) of component J3 is not driven (Net 18).** ERC messages: 2 Errors 0 Warnings 2The error on Net 16 won't go whatever I do.But, the error on Net 18 is fixed if I delete the wire connecting the B12 pin and redraw it. But a same error on occurs on the any of the capacitor in VOUT and SW network connecting to the ground. Again if I fix that the same errors is now shown on pin B1.I'm attaching the schematic as PDF below.Happy Thanksgiving.

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: November 29, 2019, 08:21:35 am
content: U1 is not driven: ERC isn'tthatsmart. I wouldn't expect it to consider it driven through a resistor. By default, ERC requires that there is a power output (which may be a flag) on every net that connects to a power input. (But you can adjust the ERC rules in the Options tab of the ERC window.)I suspect you might have another multi-named net on the ground net somewhere but I can't tell for sure as you missed the attachment again...Thanks, and same to you. It's Black Friday, stay safe out there.

author: redgear
author_rank: Frequent Contributor
timestamp: November 29, 2019, 08:25:22 am
content: Quote from: jhpadjustable on November 29, 2019, 08:21:35 amAlright then, I will ignore it.QuoteI attached it last time, idk maybe i submitted before it got uploaded.I'm attaching it with this reply. Sorry.

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: November 29, 2019, 09:03:49 am
content: Don't sweat it.Anyway, for consistency, since you're using ERC, may as well add the power flag to that net near the bottom of R1. Speaking of consistency, I see that you're using a GND sheet label instead of a ground power symbol to connect pins A/B-1/12 of J3. ERC might not appreciate that, especially without any PWR_FLAG drivers on the GND net (that I can see).Other than that, looks good. Ship it!

author: redgear
author_rank: Frequent Contributor
timestamp: November 29, 2019, 09:19:54 am
content: Quote from: jhpadjustable on November 29, 2019, 09:03:49 amThank you. I have made the changes.

author: redgear
author_rank: Frequent Contributor
timestamp: November 29, 2019, 10:19:33 am
content: Quote from: jhpadjustable on November 28, 2019, 11:15:27 amAll I could do now is just recreate the reference designs on datasheets. How are you able to tell functions of the components just by looking at the datasheet? How do I learn to understand the functions of the components(caps, resistors,etc), sizing them and start designing my own circuit?Thanks

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: November 29, 2019, 12:58:07 pm
content: Quote from: redgear on November 29, 2019, 10:19:33 amI'm not exactly a power/analog whiz kid, certainly not compared to some of the great minds here. It just happens that I've been working on some dc-dc converter and LED driver circuits lately, and reading dozens of datasheets and several app notes as part of that, so the tropes of that genre (so to speak) are fairly fresh in my mind.I did read a lot on and around the subject starting in elementary school, where I got familiar with the symbol language even if I didn't quite fully comprehend half of it, and in high school I knew a crazy guy down the block who mentored me for a few years, taught me quite a bit about the fundamentals of the art and science of electronics, walked me through a few designs and repairs, and set me up with my first decent soldering iron and a stock of useful components.The Art of Electronicsis a well-renowned intro book, with a new edition reportedly coming out sometime next year. I've followed a few Kickstarter and pre-Kickstarter blogs dealing with the trials and tribulations of developing an electronic product to be offered for sale, and from them gained some awareness and understanding of some of the concerns involved in bringing a product to market, and about the economics of manufacturing in small scale. Needless to say, I've also been watching Dave's videos and reading any topic on this forum where something half interesting comes up. Amazing teacher that he is, he always leaves me at least one thing to scream at him through the screen about.Wikipedia is not the worst possible reference for getting the gist of some sort of circuit or component unfamiliar to you, say, a buck dc-dc converter, or a broad comparison of different kinds of capacitors. These days, a lot of electronics is knowing about the blocks in common use and considering how they fit together. Indeed, only knowing how to combine a bunch of reference designs onto a single board and validate the result, you can get somewhere. It may not get you hired but you can make some things.In other words, it's something you develop with time and experience and lots of reading (and brick imprints on your forehead). Set yourself up with some decent tools. Learn about the building blocks that are out there, whether those are single transistors to SDRAMs, op-amps to optical data transceivers, and learn about their performance and their critical requirements. Read datasheets. Self-assign some projects that use those blocks. Make the project happen or figure out why you can't. Repeat until you stop breathing.

author: redgear
author_rank: Frequent Contributor
timestamp: November 30, 2019, 10:03:57 am
content: Quote from: jhpadjustable on November 29, 2019, 12:58:07 pmCan you recommend me some blogs?QuoteWhere can I find a list of such important building blocks to learn?Thanks

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: November 30, 2019, 11:14:12 am
content: Lost to the sands of time, unfortunately. The first such blog that started me on the mode of research was for a fancy RF photo-flash trigger by the name of Radiopopper. I don't believe that blog is still up with its original content, but you might be able to find it in the Wayback Machine by way of the Strobist photography blog. It didn't differ too much from the updates that you would see today on any given electronics-based project on Kickstarter or other crowdfunding platform. Dave's developed a few products and vblogged a bit about the process, most recently the µSupply, which should give you some idea of the concerns of a product designer.The "blocks" I'm talking about are just a vague, non-enumerable abstraction covering many levels of structure, akin to sentence or phrase structures. Transistors are akin to "The dog barked", short and simple but with plenty of room for subtlety, and SDRAMs are akin to "A man, a plan, a canoe, pasta, heros, rajahs, a coloratura, maps, snipe, percale, macaroni, a gag, a banana bag, a tan, a tag, a banana bag again (or a camel), a crepe, pins, Spam, a rut, a Rolo, cash, a jar, sore hats, a peon, a canal--Panama!", quite symmetrical yet twisted to get in and out of. There are no exhaustive lists, but you can occasionally find the odd category list on Wikipedia such ashttps://en.wikipedia.org/wiki/Category:Single-stage_transistor_amplifierswith somewhat comparable variations on a theme.In any case, you have to start with the rudiments. The maker movement and some of their leading distributors (Sparkfun, Adafruit) have come out with their own elementary electronics instruction resources and walk-throughs, sometimes centered around the Arduino physical computing platform. If that's not serious enough for you, Forrest M. Mims III has published a ton of renowned instructional texts and mini-notebooks, includingGetting Started in Electronics.The Art of Electronicsis more straightforward and might intimidate some beginners not accustomed to close reading, but I don't think you'll be too intimidated by it, especially when you can use the web as an auxiliary resource. If radio interests you, the ARRL's got a lot of material online and in print for beginners on up to amateur RF engineers that might pique your interest, and getting your Amateur Extra ticket is a decent test of your knowledge of the basics of RF and of electronics in general. It all depends on where you want to go.