EEVblog #1147 - 1 Cent Regulator! That's MAD - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: November 15, 2018, 10:17:54 pm
content: Is a *1 CENT* LDO voltage regulator any good?Dave tests the Shen Zhen Fine Mad! SC662K 3.3V LDO from LCSC:https://lcsc.com/product-detail/Low-Dropout-Regulators-LDO_SC662K-3-3V_C83932.htmla.k.a.http://www.superchip.cn

author: johnlsenchak
author_rank: Frequent Contributor
timestamp: November 15, 2018, 11:30:36 pm
content: What on gods earth are you going to do with 3000 voltage regulators ? Have you lost your mindGone MAD! LOLBetter lighting is needed , sound is good

author: EEVblog
author_rank: Unknown
timestamp: November 15, 2018, 11:33:27 pm
content: Quote from: johnlsenchak on November 15, 2018, 11:30:36 pmI think the sound is not great. Was experimenting with the NTG-1 mic though.

author: bd139
author_rank: Super Contributor
timestamp: November 15, 2018, 11:38:17 pm
content: I keep buying unknown brand chinese stuff from LCSC. Discretes, semis, the lot. Always works. Always in spec. I was suspicious at the start so breadboarded some of the parts. Zero problems.Don't mind waiting a couple of weeks for snail mail if the price is 1/20th of local suppliers and branded parts.

author: maginnovision
author_rank: Super Contributor
timestamp: November 16, 2018, 12:21:21 am
content: I would've liked to see noise but otherwise it looked alright.

author: jnissen
author_rank: Regular Contributor
timestamp: November 16, 2018, 01:07:58 am
content: Worth de-potting this design to see what the chip looks like. I wonder if it's like many other design in China that have "borrowed" some other manufacturers IP.

author: cdev
author_rank: Super Contributor
timestamp: November 16, 2018, 01:22:55 am
content: Love the "Mad" name just like that.

author: scopeman
author_rank: Frequent Contributor
timestamp: November 16, 2018, 03:16:22 am
content: Dave,From the data sheet it looks like the output device is a FET not a PNP. Interesting though.Sam

author: TheRevva
author_rank: Regular Contributor
timestamp: November 16, 2018, 04:32:23 am
content: Since this video refers to cheap vregs from LCSC.com, this is _almost_ 'on-topic'Has anyone used the link on JLCPCB.com to coalesce your PCB order with the corresponding parts from LCSC.com?(It should help to trim shipping costs?)I've got a little project where I'm driving a handful of 10mm pitch outdoor RGB LED displays (128 * 32 pixels) using an Arduino Due through a little shield I've designed.I had the v1.0 PCBs made @ PCBWAY and they came out fine (aside from a small 'design SNAFU' I made)I was about to hit the 'go' button on the v1.3 PCBs (v1.1 and v1.2 never saw daylight... LOL), but I thought I might give a different PCB house a try.

author: Monkeh
author_rank: Super Contributor
timestamp: November 16, 2018, 04:39:11 am
content: Quote from: TheRevva on November 16, 2018, 04:32:23 amYes, it was a farce. The two orders arrived two weeks apart.

author: EEVblog
author_rank: Unknown
timestamp: November 16, 2018, 04:46:00 am
content: Quote from: scopeman on November 16, 2018, 03:16:22 amP channel FET, I said that in the video.

author: Krumm
author_rank: Contributor
timestamp: November 16, 2018, 06:36:45 am
content: Dave, thought of doing a video on the differences between a known decent brand vs something like this? Would be interesting to know exactly why the major brands are much more expensive vs this.

author: mancausoft
author_rank: Contributor
timestamp: November 16, 2018, 09:54:34 am
content: It is interesting to see the data of 100 (or more) of these regulators, to see how accurate they really are.And of course thermal on max load

author: DutchGert
author_rank: Frequent Contributor
timestamp: November 16, 2018, 09:59:15 am
content: Nice one.What i dont like is that you connect the thing with no input or output caps on them and then start doin all kind of "tests" and draw conclusions based on that.Why not take 5 mins extra an connect the suggested caps to them and do all these tests.Also, i doubt any serious western company will use these parts. You can test them and so on but what about the next batch or the one after that…… I would not trust the next reel that comes in for one bit

author: iMo
author_rank: Super Contributor
timestamp: November 16, 2018, 10:02:38 am
content: People get oscillation problems when loading some LDOs vregs with ceramic capacitors.Try with 10-22uF ceramic multilayer wired directly at its output..

author: Warhawk
author_rank: Frequent Contributor
timestamp: November 16, 2018, 08:42:41 pm
content: The price of such a component does not compensate for the risk associated with using them. The manufacturer would probably need to pay me for using a component with no English datasheet, single distributor, doubtful performance and zero quality assurance. Dave, I like your videos where you discover bizarre Chinese stuff but I don't like the optimism I sense from the video(s). I like the critical-thinking and skeptical Dave simply better. The Dave some time ago would not waste his precious time on 1 cent LDOs, 3 cent micros, and 20USD AN8008. There are enough YouTubers from the 3rd world countries which can take care of it.Keep in mind that you have become a respectful industry influencer and your videos don't only entertain senior engineers but also educate young graduates. We (you) should educate the young folks that an HW designermustdo the best to deliver a functional hardware. This means quality first. Even a skilled hobbyist doesn't waste his time working with unknown brands (you remember widlarizer, right?).Cost optimizations are for idiot managers, marketers and the procurement department. They behave like on heroin anyway - you save them a cent, they want you to save two.However, working for TI and traveling to China every so often makes me probably biased. Or maybe I've just had a bad day today and now being hysterical. I should probably watch another episode of Dilbert.Take care and thanks for all the time you invested in popularizing electronics.- Jiri

author: bd139
author_rank: Super Contributor
timestamp: November 16, 2018, 08:47:21 pm
content: That "bizarre Chinese stuff" is in everything around us too.

author: cdev
author_rank: Super Contributor
timestamp: November 16, 2018, 08:52:34 pm
content: bd139,have all the components you've bought worked consistently?The question of consistency is a valid one. Suppose a one cent voltage regulator works great for a while and then suddenly fails, it definitely is relevant to the decision of whether to use them.All parts should be held to the same standards as far as quality.We remember the bad experiences much more than the good ones. It only takes one key component (like a voltage regulator!) to fail to ruin a device.If they are reliable, though, thats good news for designers who want a low price option.I know that its nice to have a part when you need one. These parts are so cheap that stocking up on them is not painful.If you don't need them for a while, no biggie. You'll have them when you do.bd139, I'd like to hear more about the unknown Asian parts you've found that you liked or didn't like and why.

author: bd139
author_rank: Super Contributor
timestamp: November 16, 2018, 09:44:04 pm
content: Quote from: cdev on November 16, 2018, 08:52:34 pmI'm relatively early in the journey. So far we have:1. No brand MLCC C0G/NP0 caps. Cheapest they have on LCSC. As good as Vishay mono-kap C0G in VFO applications. I managed to get VFO drift of only 18Hz/hour out of them. That is better than the other generic MLCC ones I've used which are supposedly C0G/MP0.2. HT7550 from Guandong Hottech. I've tried a sample of these (10 off) with stupid loads (long bits of wire with caps on the end, reels of wire with resistors on end) and they are rock solid. I managed to get MCP1700s to oscillate and a TI part I can't remember to do that too. Cheap ones, not a sausage. I checked dropout under varying load conditions, all good. I checked short circuit handling, transients. All good.3. Cheap resistors. Nothing in them. They just work. Tempco seems about right. If I wave the board over a gas cooker there's little change in resistance even though it toasted my Pomona leads4. Changzhou Starsea Elec LL4148. £0.0073 each. Tested in switching function and breakdown - seem as good as any other parts.I have a couple of boxes of parts in flight which I will evaluate.I bought some LEDs as well. Those were fine but I'm not sure they met the brightness spec but that may be because there's no diffuser.The point is really this:1. LCSC: LL4148 x50 = £0.365.2. RS: £24.00 -You can pick major brands as well if you need to. I bought some ON semi MMBF4416's for £0.08 each. Same as UK disties but I don't want min quantity 100 off

author: jancumps
author_rank: Unknown
timestamp: November 16, 2018, 09:45:25 pm
content: Once you turned to the bench, there was something off with the sound. Distorted a little , and no lows.

author: Warhawk
author_rank: Frequent Contributor
timestamp: November 16, 2018, 10:01:03 pm
content: Quote from: blueskull on November 16, 2018, 08:55:11 pmHere in Europe, we typically have respect for the competition. Your assessment does not offend me at all. However, it is rather limited and stereotyped. You forgot about NXP, Renesas, JLR, ST, IFX, Microchip, Maxim, IDT, MPS, Rohm and many many others. And guess what - I am well aware how and where they are good (because they are!).PS: LTC has been my favorite since ages.PPS: My comment was not a pissing contest on who has better components. I am an engineer. Not a football fan.

author: sakujo7
author_rank: Contributor
timestamp: November 17, 2018, 03:02:37 am
content: Quote from: TheRevva on November 16, 2018, 04:32:23 amI tried it about a year ago, and everything arrived in one box. YMMV.

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 17, 2018, 03:54:51 am
content: Quote from: blueskull on November 16, 2018, 08:55:11 pmAgree with that ranking.

author: EEVblog
author_rank: Unknown
timestamp: November 17, 2018, 07:12:56 am
content: Quote from: Warhawk on November 16, 2018, 08:42:41 pmYes, you are having a bad day.These one cent regulators exist, they work, and they are used in their squillions in devices you own and use, and are one of the reasons why stuff you can buy is so cheap.Therefore they are worthy of being discussed.

author: EEVblog
author_rank: Unknown
timestamp: November 17, 2018, 07:16:32 am
content: Quote from: DutchGert on November 16, 2018, 09:59:15 amBecause it's a worse case test. If it works worst case it's going to be only better when compensated ass recommended.

author: BrianHG
author_rank: Super Contributor
timestamp: November 17, 2018, 08:08:25 am
content: Quote from: EEVblog on November 17, 2018, 07:12:56 am

author: G0MJW
author_rank: Regular Contributor
timestamp: November 17, 2018, 08:32:03 am
content: Not sure that's true Dave, you tested them with wires and some caps but inductive loads and low ESR caps might upset them. Don't know until tested. I expect these are just as good as the more well known parts, possibly because they are based on the more well known parts.What are you going to do with the remaining 2999 3.3V regulators?Mike

author: Warhawk
author_rank: Frequent Contributor
timestamp: November 17, 2018, 09:36:58 am
content: Quote from: EEVblog on November 17, 2018, 07:16:32 amI agree with @DutschGert. Everything you measure outside the operating envelope of any IC has low if any value. Most importantly, you took no notice of the output capacitance of the BK precision electronic load. I would be surprised if there wasn't any cap on the output. The DS recommends 1uF for the input and the output cap. This is probably close to what you can find in the BK load.The right (and cheap) way to test the step response is a low-inductance resistive load, signal generator, and a mercury-wetted relay. The regulation loop in electronic loads can do goofy things when testing the stability and transient response. I've already burned my hands a few times.Just my 2 cents on the 1 cent LDO

author: nctnico
author_rank: Super Contributor
timestamp: November 18, 2018, 02:51:39 pm
content: Quote from: bd139 on November 15, 2018, 11:38:17 pmBetter do some thermal cycling testing to see if these parts survive long term. My experience with cheaper parts is not good when it comes to life expectancy. In some cases I've seen a 100% failure rate when installed in the field after less than 2 months.

author: floobydust
author_rank: Super Contributor
timestamp: November 18, 2018, 04:51:19 pm
content: Quote from: Warhawk on November 16, 2018, 08:42:41 pmI too see no magic in these penny semiconductors.They exist due to currency devaluation, stolen IP, dumping, industrial subsidies, severe environmental neglect etc. Yes it is MAD.Proof is none of us could even buy the epoxy or pins for the cost of the part.

author: bd139
author_rank: Super Contributor
timestamp: November 18, 2018, 04:53:50 pm
content: Your expensive bits are the same though but it’s costing you the deeper supply chain, fancy air conditioned offices in the US etc.

author: Fungus
author_rank: Super Contributor
timestamp: November 18, 2018, 05:54:45 pm
content: Quote from: blueskull on November 18, 2018, 04:55:32 pmThat's what Trump is trying to do in the USA.

author: floobydust
author_rank: Super Contributor
timestamp: November 18, 2018, 06:18:48 pm
content: What we should be discussing why a similar part in North America is priced over 10-30X higher, tariff includedAn LDO has nothing for technology, it's a jellybean part. 3,000-lot (a reel):Diodes Inc. AP7313-33$0.1110 ea.Microchip MCP1700T33$0.2884 ea.If we look at "fat" in the distribution supply chain, is the markup really that high?The raw materials copper, steel, aluminum comes from Australia and is processed in china and then comes back at a lesser price. You have to wonder.inb4 politics derails thread

author: bd139
author_rank: Super Contributor
timestamp: November 18, 2018, 06:21:16 pm
content: Staff gotta buy their Model S. In China you get public transport or bike to work.West is very used to luxuries that don’t scale. Watch this space over the next 20 years.

author: Warhawk
author_rank: Frequent Contributor
timestamp: November 18, 2018, 07:59:42 pm
content: Just do the search on octoparts. I see an LDO from onsemi from newark for 5 cents or Toshiba 6 cents for 1ku price.https://octopart.com/search?q=3.3V%20LDO&start=0&sort=median_price_1000&sort-dir=asc

author: splin
author_rank: Frequent Contributor
timestamp: November 19, 2018, 12:51:39 am
content: You can do your own qualification testing and much of that will be simple and cheap as demonstrated in the video. But some issues are rather more problematic. In particular ROHS - how much does it cost to get a lab to test a part for compliance?If you buy a part that is used in products widely sold in the EU then it is almost certainly compliant, but it probably won't be easy to determine that that is the case with your specific part, especially with the preponderance of Chinese equivalents, clones, knock-offs etc. A Padauk micro is unlikely to be copied so you only have that company to worry about, but jellybean parts such as LDOs? You are in a maze of twisty little passages, all alike.Even if you buy a part from the same manufacturer, who you know to supply complaint ROHS parts for those top-tier companies selling in Europe, how can you be certain they don't have a reduced cost product line using the same silicon but packaged in cheaper, non-compliant, plastics intended for other markets? We known the Chinese are very adept at shaving a few centi-cents off already rock bottom prices.The part number may even be identical. Sure a reputable company will have proper QA, certification, traceability etc. but then their prices may well reflect that. There must be a great deal of smaller/mid size Chinese companies, especially those competing at the lowest price points, with somewhat less, shall we say 'rigor' in their internal processes/stock control/documentation - whether accidently through aggressive cost cutting or deliberate when scruples are trumped by sales figures/profit margins.Your regulators were marked lead free (and ROHS bans many other substances such as phalates), but unless you have them tested yourself it comes down to a matter of trust. If you get sued you could go out of business and countersuing your Chinese supplier would likely be fruitless or impossible. Digikey/Mouser etc. may also make mistakes (and you may have little more redress if you suffer as a result), but you would expect them to have good enough processes in place such that you don't have to worry about it (ie. you trust them), and/or plead best practices etc. in your defence.Bottom line, I expect very few will have a problem ith ROHS and probably most small to medium sized manufacturers get away with ROHS non-compliance (especially Ebay resellers of cheap Chinese products) anyway - after all, who has the resources or interest in enforcement? Customs may well pick up lead bearing components with suitable scanners, but Bromides etc? So perhaps a non-issue to most, or those who can afford to write-off a faulty batch, but a real problem for some.

author: ebclr
author_rank: Super Contributor
timestamp: November 19, 2018, 04:22:53 am
content: "They exist due to currency devaluation, stolen IP, dumping, industrial subsidies, severe environmental neglect etc. Yes it is MAD"But they exist and are inside all products peoples buy-in mass, Look at your home and find for made in China in near everything you have in your home and the ones that do not have you pay a 10X premium for that.It's a reality and will be even worse since China is no more copying only they are now developing and branding and any political force to fight against ( like Trump Tariffs) will be a disaster, with instantaneous inflation and only a few ones with buying power to have those things.Isn't the Chinese the fault, The Falt is from westerns paying to much in bonus, regulations, and marketing, Even creating IP's from nowhere just to have a monopoly. The fact is that the Chinese engineering economy is much more productive and fluid than the lawyers economy easily found is big powers.David finally wakes up, about the viability of Chinese products, Next lesson will be the discovery that isn't only Nichicon the unique viable good quality capacitor on earth.

author: floobydust
author_rank: Super Contributor
timestamp: November 19, 2018, 06:52:00 pm
content: The top 10 electronics distributors made$77.3 billionin revenue in 2017:https://www.sourcetoday.com/distributor-news/top-50-electronics-distributors-restarting-growth-and-running-itImagine that- you buy a widget, markup the price, sell the widget and make piles of money.The penny price comes from bypassing the distribution and sales chain, going direct to the manufacturer in china.But in the end -price really doesn't matter to engineers. Our paycheque stays the same if the product costs more. Any bonus, commission etc. goes to sales and the executives.Blaming the West for paying too much in bonuses, regulations, marketing- it is true.But I also see your countrymen parading around in Mercedes and BMW, buying up real estate, so there is the same "fat" in that economy also, it just looks different.

author: thm_w
author_rank: Super Contributor
timestamp: November 19, 2018, 08:46:14 pm
content: Quote from: floobydust on November 18, 2018, 06:18:48 pmLCSC has the MCP1700T for $0.17 ea, so there is some digikey markup:https://lcsc.com/product-detail/Low-Dropout-Regulators-LDO_MICROCHIP_MCP1700T-3302E-TT_MCP1700T-3302E-TT_C39051.htmlMicrochip themselves sell it for 28c each as well, maybe there is an agreement there.Also on aliexpress the MCP is about 7 or 8c, but you have to be a lot more careful inspecting the parts when received to verify they are not fake. Upside is, that price can be had at only 200pc qty.Most likely factory overrun, not a proper production source, but good for hobbyists.

author: coppice
author_rank: Super Contributor
timestamp: November 19, 2018, 08:55:14 pm
content: Quote from: bd139 on November 18, 2018, 06:21:16 pmI guess that's how China became the world's largest car market.A huge number of Chinese engineers have their own car, or drive a company one. Not as many as in Europe or America, perhaps, but its a few years since car ownership was rare.

author: MadScientist
author_rank: Frequent Contributor
timestamp: November 29, 2018, 11:52:31 pm
content: Quote from: Fungus on November 18, 2018, 05:54:45 pmActually it’s not , he’s erecting tariffs barriers to essentially make higher priced domestic production “ competitive “ by essentially excluding cheaper competitive sources. That’s the exact opposite of what you espouseUltimately chinas production costs can only go one way , up , they all want to drive BMWs too you know

author: coppice
author_rank: Super Contributor
timestamp: November 30, 2018, 09:58:06 am
content: Quote from: MadScientist on November 29, 2018, 11:52:31 pmIt appears he is trying to improve local wages by making things so much more expensive in the shops that the improved wages will buy less than before. Tariffs don't improve productivity. Only improved productivity improves people's ability to buy stuff.

author: tszaboo
author_rank: Super Contributor
timestamp: November 30, 2018, 02:06:06 pm
content: Quote from: floobydust on November 19, 2018, 06:52:00 pmIDK about you, but as an engineer, I dont buy anything. That is the job of the supply chain, the same with negotiating prices. I usually dont have time to do these negotiations anyway, because time to market is supposed to be yesterday, and it supposed to be compliant with half a dozen regulations, that take half a year to get.

author: coppice
author_rank: Super Contributor
timestamp: November 30, 2018, 02:53:14 pm
content: Quote from: floobydust on November 19, 2018, 06:52:00 pmMost people in China don't source from the manufacturer. There are greater problems getting paid in China than in other places. For large orders, where a vendor would serve a US or European customer directly, most Chinese customers are served through a distributor. The vendor will usually provide engineering support, just as they would for any large customer they serve directly, but the distributor deals with the rolling debt issues.Quote from: floobydust on November 19, 2018, 06:52:00 pmWhat kind of weird engineering are you involved in, where the BOM doesn't rule most engineering decisions? If the BOM isn't optimised there is no pay cheque.

author: floobydust
author_rank: Super Contributor
timestamp: November 30, 2018, 07:36:18 pm
content: Many engineers go through the painful lesson of choosing the lowest cost part, worse so from a foreign supplier.Price as priority #1 for the BOM cost, is a fool's mistake.What you will experience is phone calls from Production or Customers having problems with the product.The 'little penny LDO that could' turns out to be out of spec for voltage, noise or oscillating at end temperatures, going into shutdown etc.This is when the engineer learns, the hard way, that chinese datasheets have exaggerated numbers, missing specifications, typos, translation errors and no support available. The silicon has wide test limits and is loosey goosey.What did you expect for a penny? Now, do you recall the sold products and replace the LDO? Do you try a bodge? Wait for a few reels of new parts? Or let customers live with a low quality product?There is huge risk for the designer using parts such as this. Ultimately his/her paycheque stays the same, but the hassle and responsibility for choosing that vendor and the consequences are the engineer's. It is false economy to think money was saved, as there would be no drama using a more expensive part.Looking at this part's datasheet, it's a cut'n'paste from some other manufacturer, full of typo's conflicting numbers and missing some very important characteristics. Many traps here.The Arduino crowd won't notice but it's like walking into a casino to use this part in production of high quality product.

author: nick_d
author_rank: Regular Contributor
timestamp: December 18, 2018, 07:49:04 am
content: What the fakers generally do is put together a workalike of a well known part using IP library modules from their silicon supplier. Thus, if the library modules are well designed the part will work well. Where it can run into problems is that the library approach will use twice as many transistors as the genuine part as there will be well defined interfaces between the library module, so advanced uses of the part where the user has checked the official circuit to see what voltages, currents etc are produced internally when the chip is placed in unusual situations, won't work. An example of this is with the "LM386" chips I bought, the bias pin is supposed to have a certain voltage or resistance etc on it, and in my case I was using this to do advanced stuff like nulling a DC offset so that I could directly drive a speaker with no output filter. Did not work, because the fake is internally structured as an ordinary op-amp connected up to just RESEMBLE an LM386. It would work fine for ordinary, undemanding applications such as children's toys, and as said above, they're EVERYWHERE. The only real issue I have with this is the deceptive conduct. With a proper datasheet it would be a great part. That's why this LCSC gig is great in my opinion.cheers, Nick