Buying ICs from Alibaba/Aliexpress

[bitshift]

Hey guys,

I'm trying to source a certain IC in South Africa. My only options seem to be mouser, digikey or alibaba/aliexpress. The IC in question is the NRF24L01P 2.4GHz transceiver from Nordic.

From http://www.aliexpress.com/item/Free-Shipping-10-pieces-lot-100-NEW-NORDIC-NRF24L01-NRF-24L01-2-4G-RF-IC-CHIP/2045680180.html I can get 10 for USD9.50 with free shipping to South Africa. 

From http://www.digikey.com/product-search/en/rf-if-and-rfid/rf-transceivers/3539948?k=nrf24l01p the same would cost USD16.2 excluding shipping.

There is a significant difference in cost between the two. I would like to leverage off of your guys experience before deciding what to do. Any feedback and experiences would be greatly appreciated.

[Psi]

Chips from aliexpress can be a bit unpredictable.
Most of the time they're perfectly fine but the thing i worry about is factory rejects from the legit manufacture. Those often get sold off on places like aliexpress.

[bitshift]

the thing i worry about is factory rejects from the legit manufacture.

If you do end up getting factory rejects would this imply that in some way they didn't meet their required spec according to the datasheet?

With that in mind I would think the saved cost would not be worth the potential headache?

[Psi]

Yeah, that's the problem.
The factory rejects normally do work, they just have performance issues

[bitshift]

Going to go the DigiKey/Mouser route rather. Thanks for your help 

[that_guy]

That particular IC (the NRF24L01) is one that is known to be cloned. Google "NRF24L01 fake" for the stories.

[Obin]

Ordering cheap components can go in 3 ways:

- I once ordered a few ua741 opamps for something like 1 euro from ebay once: all broken. they litteraly did nothing.
- Another time i ordered a few opamps wich also were cheap, but they all worked fine. I did notice they had soms marks on the "legs" so they were most likely harvested components
- Or everything is fine (most of the time). I personally never had an issue with aliexpress. Apart from the shipping everything is fine (just yesterday i got a free dead spider with my 3pdt switches!)

edit: If you want to play safe, mouser would be your best bet

[charlespax]

It's fine to order passive components from Aliexpress or Taobao. ICs are okay too, but you have to look at ratings and reviews. There are plenty of good sellers out there. If you go the Taobao route, you can use http://dev.dangerousprototypes.com/store/taobao

[bitseeker]

but you have to look at ratings and reviews. There are plenty of good sellers out there.

+1

Since there are often many vendors selling the same items, be sure to read the reviews. If a seller hasn't sold any quantity of the item or hasn't received any feedback on it, check a different seller. Better to pay a little more to a seller that shows some buyer confirmation.

[nwvlab]

It's fine to order passive components from Aliexpress or Taobao. ICs are okay too, but you have to look at ratings and reviews. There are plenty of good sellers out there. If you go the Taobao route, you can use http://dev.dangerousprototypes.com/store/taobao

no, it's not fine, even for some passives! Almost all the ceramic capacitors I purchased from aliexpress were fake. Either disguised as X7R (whereas they were Y5V), or they had much lower voltage ratings. I characterized them using a E4980A precision LCR meter (performing C-V measurements) and I compared the results against genuine caps... I will post them if anyone is interested.

Positive feedbacks are almost useless: many people have no access to such LCR meters (or they do not have enough knowledge so they do not bother doing a C-V measurement) and, at most, they simply measure the capacitance with a DMM...  And they leave a positive feedback anyway.

Cheers

[lem_ix]

Aliexpress arduinos working fine for me, several mates happy with components. No problems so far.

[AdamHi]

I do both - sometimes buying parts from prime dealer (eg, Mouser or DigiKey), other times from eBay or similar. if i'm trying to learn or develop something - and something doesn't work - i usually assume it's ME and not the part. I could waste a boat-load of time trying to figure out what I did wrong - when it was just the $1 part that was junk.

Electronics is my hobby, and i find it enjoyable. I'd love to spend more productive time in the hobby - but time is what I don't have lots of. Usually it's just not worth it. Wasted time has a value . . .

--adam

[orolo]

I do both - sometimes buying parts from prime dealer (eg, Mouser or DigiKey), other times from eBay or similar. if i'm trying to learn or develop something - and something doesn't work - i usually assume it's ME and not the part. I could waste a boat-load of time trying to figure out what I did wrong - when it was just the $1 part that was junk.

Electronics is my hobby, and i find it enjoyable. I'd love to spend more productive time in the hobby - but time is what I don't have lots of. Usually it's just not worth it. Wasted time has a value . . .

I'm also a hobbyist, and I've found myself relying more and more in mouser over ebay or alibaba. I've found that jellybeans, like discrete transistors, aren't that expensive when bought in quantity, and the certified origin is a bonus even for a hobbyist. For example, compare a genuine 2222 with a clone  to the die level: if I use a 2222, it is because it handles more power and because it has greater beta than a 3904 at higher currents. From the dies I suspect that the cloned transistors are produced in mass, and then labeled 2222 or 3904 or BC548 or whatever, as needed. I can get 100 fairchild PN2222 for 5.4 euro from mouser; that beats 100 clones for $1 of unknown reliability. I have some ebay 1N4007s that I dare not use for anything serious: their leads are much thinner than the legitimates I own. Are they just relabeled generic 1N400x, with no quality control at all? I suspect they might fail if taken to high currents or voltages, even within spec. Sometimes, ebayers sell landfill material: once I got a pack of 100 germanium diodes with the crystal encapsulation broken in every one unit. Where did they come from?

To make it short, I would drop the label from anything ebay. They sell generic transistors, generic small diodes, generic bigger diodes, generic low precision op-amps, and so on. Operated well within ratings, they should work decently, but that is all. For anything specific, and that includes complex chips, I buy from certified sellers.

Regarding the original post, zeptobars has an analysis of a NRF24L01+, genuine vs fake. I find it fascinating that they went to the extreme of designing their own working (to what specs?) clone from scratch. That takes a great deal of talent. Then they go and sell it marked as genuine, which is downright dishonest. I wouldn't ever promote such behavior.