Knock off chips? - Page 1
Forum section: electronics / general

author: wadmancpu
author_rank: Contributor
timestamp: March 17, 2019, 02:51:23 am
content: Hello, I've been buying some voltage controller qfn chips from ebay and the last batch seemed mostly defective. These are ISL9860 chips allegedly made by Intersil. I ordered from another supplier and the print on them is much brighter and clearer, even a bit of a different color. I was wondering how many knock offs of components are floating around out there and how many of you have run across them? Not saying for sure that these are but it certainly looks suspicious. Thanks all.

author: DerekG
author_rank: Frequent Contributor
timestamp: March 17, 2019, 03:16:24 am
content: Quote from: wadmancpu on March 17, 2019, 02:51:23 amThere is an entire industry in China that de-solders components from old PCBs & then resells them as new, often with no testing taking place to confirm the component is still operational.There is also a large industry that re-numbers lower spec components as higher spec components. This is particularly prevalent in the high voltage arena of MOSFETS, transistors & voltage suppressors.You can only be guaranteed of avoiding these "grey" parts by buying direct from an authorised supplier.

author: james_s
author_rank: Super Contributor
timestamp: March 17, 2019, 03:57:27 am
content: Yet another industry takes large quantities of useless obsolete ICs and relabels them as completely different much more useful parts. Sometimes you can find a bargain on genuine parts and sometimes clone parts are quite good. The problem is you can never tell what you're getting until you get it. For hobby projects I don't worry about it too much but if I were producing items for sale I'd buy from a reputable distributor.

author: Warhawk
author_rank: Frequent Contributor
timestamp: March 17, 2019, 07:05:01 pm
content: Quote from: james_s on March 17, 2019, 03:57:27 amMy hobby time is so precious that I would not bother even thinking about buying any IC from eBay or other sources know for counterfeits.

author: Gyro
author_rank: Super Contributor
timestamp: March 17, 2019, 07:17:29 pm
content: Quote from: wadmancpu on March 17, 2019, 02:51:23 amA forum search for 'fake' will yield the extent of this problem. Too numerous to mention.

author: james_s
author_rank: Super Contributor
timestamp: March 17, 2019, 07:26:35 pm
content: Quote from: Warhawk on March 17, 2019, 07:05:01 pmWell sometimes you can't get a part from a reputable supplier anymore, other times the cost is prohibitive. For example I used a VGA DAC in one of my projects for a purpose other than it was originally intended. From DigiKey it would have been around $18 each, instead I bought 10 of them for $25 from an ebay seller and they worked perfectly. The Maxim LED drivers are the same story, $5-$10 each for the IC alone from reputable sellers but I can get one on a board with an LED matrix or 7 segment displays for a couple dollars and they work perfectly.

author: wadmancpu
author_rank: Contributor
timestamp: March 18, 2019, 05:49:21 pm
content: Thanks for all the replies. I just ordered some from mouser. About $6 a piece and $7.99 shipping compared to 5 for about $10 and free shipping on ebay. At least I can be confident on the quality.

author: DerekG
author_rank: Frequent Contributor
timestamp: March 18, 2019, 09:37:19 pm
content: Both Mouser & Digikey offer free shipping if you meet their minimum spend (which is not very much).

author: wadmancpu
author_rank: Contributor
timestamp: March 18, 2019, 11:50:39 pm
content: Yeah, I paid for FedEx second day with mouser because I've lost too much time already messing with ebay junk.

author: james_s
author_rank: Super Contributor
timestamp: March 19, 2019, 04:11:38 pm
content: Quote from: blueskull on March 18, 2019, 09:50:14 pmI recently tried Arrow due to the free shipping. I was pleased with the service and the parts but man, they get the award for the most wasteful packaging. I received my $15 order in three separate boxes, one of them enormous and containing a 3' long IC tube with one 8 pin DIP in it and a long strip of foam. Each part was inside a separate ESD bag, including each strip of 10 SMD resistors. Each of those was inside an outer plastic bag and each came with a separate paper invoice. The weight of packaging to parts was probably 10:1 and the volume 1000:1.If I wanted ESD bags or other packing materials it would be cheaper to order a bunch of the cheapest components they carry, throw away the parts and keep all the bags.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: April 21, 2019, 12:16:10 am
content: Have you ever considered LCSC?It's more expensive than Ebay / Ali / China_ripoff_store, but often about half the price compared to Mouser / Digikey / Farnell / Westen_Extortionists, while quality is comparable, and they also sell lots of products that are not available from those Werstern Extortionists.Do you see 5ct Padauk Microcontrollers on those shelves?I'm guessing that the Microchips, MSP's and other uCls cost about as much to manufacture nowaday's as the Padauk's, but why would they sell them cheaper as long as they have enough customers willing tho pay their prices?In this capitalist werstern world there is *** NO CORRELATION *** between the price to manufacture something and the price you have to pay to buy it. There is only one single exception. If customers are not willing to pay more for a product than it costs to manufacture, the produt ceases to exist.

author: OwO
author_rank: Super Contributor
timestamp: April 21, 2019, 04:00:00 am
content: I get my parts almost entirely from taobao and LCSC, and have yet to encounter a single fake. I've used ~1000 taobao chips in products, and have yet to get a report of malfunction of any of my products. You do need to be smart about it though, mainly you need to check the feedback history of a seller and correlate prices across popular listings (if a lone seller is offering at an outlier price compared to everyone else that's reason to be suspicious).Authorized distributors are like car dealers and record labels. The manufacturer doesn't wish to deal with logistics so it signs deals with distributors, but all the established ones impose draconian rules like "you must force all your volume customers to sign no-resell agreements" to protect its own interests and keep low volume component prices inflated. With only a few big distributors who very likely have implicit "gentlemen's agreements" and play by the same rules, there is no competition. Only in places like China where contract violation isn't always considered a big crime do parts end up on the market at fair prices.

author: james_s
author_rank: Super Contributor
timestamp: April 21, 2019, 04:04:39 am
content: It really depends on what parts you're looking for. Hard to find/vintage/exotic semiconductors are much more likely to be fake or noticeably inferior counterfeit. More mundane jellybean parts may be counterfeit as in not manufactured by the company whose logo is printed on them, but they generally seem to work as advertised. With parts that do work reasonably acceptably it can be quite hard to tell if they're genuine or not.

author: m3vuv
author_rank: Super Contributor
timestamp: April 27, 2019, 06:08:17 am
content: ive lost count of the amount of fake crap ive had from flebay,had some 2n3055 that went sc after i tried to get half an amp out of them also some lm 388 rated at 5 amp,most i could get out was 500ma!!