Impossibly cheap Chinese breakout boards / parts - Page 1
Forum section: electronics / projects

author: DavidJRobertson
author_rank: Regular Contributor
timestamp: January 08, 2019, 12:07:04 pm
content: I've been looking at a handful of pricey Analog Devices parts for a new project. One thing I don't understand is how it's possible to buy dev/breakout boards with these parts on eBay from China for far less than the cost of the chip alone.Some examples (Pricing compared to RS, but it isn't the case that RS is unusually expensive here):AD9959 4-channel DDS, 500MSPSAvailable on a nice little board on eBay for £23 delivered, but costs £45 each excluding VAT in a tray of 260 from RS.AD9850 1-channel DDS, 125MSPSAvailable on a slightly-naff breakout board (which I wish had the output on an SMA connector) for £11 from eBay, but costs £21 each excl. VAT from RS.AD831 RF mixerAvailable on a nice board from eBay for £5, but costs £12 excl. VAT from RS.AD8302 gain/phase detectorAvailable on a board from eBay for £4, but costs £20 excl. VAT from RS.Are these counterfeit parts? Even if they are fake, they do still work just fine.... where can I buy them for these prices? Short of just buying the eBay boards and desoldering the parts, of course.

author: metrologist
author_rank: Super Contributor
timestamp: January 08, 2019, 05:06:03 pm
content: That's a nice looking module that I should pick one up. I recall this discussion before and it was speculated these (9850 at the time) were either counterfeit or factory leaks... There was also talk that one large Asian distributor may be involved in getting the price down and then piecing the distribution.

author: ebclr
author_rank: Super Contributor
timestamp: January 08, 2019, 06:54:56 pm
content: "Are these counterfeit parts? Even if they are fake, they do still work just fine...."Ta sauce will cost higher than the salad, I don't believe they are fake, They are only bought on a country where they can profit with little margin, because does not need to p[ay insurance for liability on anything and huge Bonuses for CEO's and legal departments, Cutting all those things makes possible to sell at this prices.

author: In Vacuo Veritas
author_rank: Frequent Contributor
timestamp: January 08, 2019, 07:08:04 pm
content: L9 looks like he's had enough of this and is leaving

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 08, 2019, 08:19:40 pm
content: Quote from: blueskull on January 08, 2019, 07:04:12 pmYes, but even so, if the chips are not resold as is but sold as part of development/breakout boards, I guess they can sell the boards at whatever price they see fit, just like any product that would use those chips, without even infringing anything.

author: Synthtech
author_rank: Regular Contributor
timestamp: January 08, 2019, 09:56:26 pm
content: Looks like the Night Factory has been running full steam.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 09, 2019, 01:12:59 am
content: You have some dds generators kit on ebay up to 200 mhz with touchscreens ?

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 09, 2019, 01:27:07 am
content: Quote from: coromonadalix on January 09, 2019, 01:12:59 amSomething like this:https://www.ebay.com/itm/New-AD9854-DDS-Signal-Generator-STM32-F103-Controller-Board-Touch-color-screen/183296169012It's 300MSPS so you won't get signals up to 200MHz but that's close.

author: Bud
author_rank: Super Contributor
timestamp: January 09, 2019, 01:35:52 am
content: Quote from: metrologist on January 08, 2019, 05:06:03 pmSomeone reported before it did not work properly and the wiring of the chip was weird.

author: metrologist
author_rank: Super Contributor
timestamp: January 09, 2019, 03:27:06 pm
content: Quote from: Bud on January 09, 2019, 01:35:52 amI think I found that thread here and posted in it. I did not not find much else on this module. I read something about the AD9910 being a bit off too, but performance wise.https://www.eevblog.com/forum/rf-microwave/ad9959-ebay-board-troubleshooting/https://www.eevblog.com/forum/testgear/ad9910-dds-module-420m-1msps-highest-output-sampling-frequency-signal-generator/I guess I could think about the feeltech again

author: bd139
author_rank: Super Contributor
timestamp: January 09, 2019, 03:32:09 pm
content: Let’s just say that its not eBay that is cheap but RS is fucking expensive in low quantities.I bought 10x AD8307 from aliexpress for £3. Or £10 each on RS.If you want to see how stupid RS pricing is check out SOIC breakout boards.

author: coppercone2
author_rank: Super Contributor
timestamp: January 10, 2019, 06:27:19 am
content: it might not be tested or something. look at how many specs those dds have to meet.

author: TrickyNekro
author_rank: Frequent Contributor
timestamp: January 10, 2019, 04:30:07 pm
content: Quote from: blueskull on January 09, 2019, 04:08:17 pmYup! Noticed it with Coilcraft and Microchip direct too, I can confirm!Mouser and Digikey are really for prototyping if you can afford to produce very large volumes, they got staff and bills too to pay plus profits.

author: Bud
author_rank: Super Contributor
timestamp: January 10, 2019, 05:06:44 pm
content: You have to add cost of shipping and importation, often you end up on par with Digikey and other distributors, unless you buy in suficient quantities to offset those costs. Purely looking at the sticker price on the web is delusional when stuff needs to cross the border.

author: Bud
author_rank: Super Contributor
timestamp: January 10, 2019, 05:33:25 pm
content: It is $5.99 by which carrier?

author: Bud
author_rank: Super Contributor
timestamp: January 10, 2019, 05:57:25 pm
content: so that will not work for non-US destination. UPS will also slap additional fees like fuel surcharge. Garantee, the final delivery bill will be times higher. Never in my life i got anything from UPS for that cheap even within Canada.