Possibly wrong marking on a chip from Ali? - Page 1
Forum section: electronics / projects

author: Miti
author_rank: Super Contributor
timestamp: February 09, 2020, 08:28:06 pm
content: I bought 5 chips from Aliexpress that were supposed to be MC12080, a 1.1GHz prescaller, this is the link to Ali:https://www.aliexpress.com/item/4000301840060.html?spm=a2g0o.productlist.0.0.182362b3xmZHgC&algo_pvid=fe62791f-50cf-469e-bb2a-1c8a9f60d0a4&algo_expid=fe62791f-50cf-469e-bb2a-1c8a9f60d0a4-29&btsid=e57581f6-eb8f-48be-8922-383ef52909b8&ws_ab_test=searchweb0_0,searchweb201602_10,searchweb201603_55and this is the link to the datasheet:https://www.nxp.com/docs/en/data-sheet/MC12080.pdfThe chip functional table shows divide ratios of 10, 20, 40 and 80. The chips that I received seem to have the correct pinout, but they only divide by 2, 4 and 8.With SW1 - SW3 open, I get a ratio of 8, either SW1 or SW2 high the ratio is 4 and with both SW1 and SW2 high, the ratio is 2. SW3 does nothing.The chips have Freescale logo on them.I was expecting that the chips either work or they don't work, but to somewhat work? Or maybe that's why they are sold on Ali, otherwise they would be on Digikey?Can you think of any other chip that can follow the logic described before? I tried 2 of 5 and they work the same.Edit: One more clue that they may be different chip inside, the supply current at 5V is 7mA compared to 3.7mA typical in the datasheet.Edit1: Pin 7 that was supposed to be SW3 seems to be an active low shut down. Connected to GND, the output goes high and the supply current goes down to 4mA.Thanks in advance!

author: wraper
author_rank: Unknown
timestamp: February 09, 2020, 08:31:59 pm
content: Most likely MC12093 with fake marking.https://www.onsemi.com/pub/Collateral/MC12093-D.PDF

author: Miti
author_rank: Super Contributor
timestamp: February 09, 2020, 08:48:12 pm
content: Yes, that must be it, thanks!Why would they do that? Digikey price is the same for both chips.There's something wrong with the chips, other than the marking. SB current should be 50uA, in my case it is 4mA. Little big difference.I've already opened a refund request with Ali.

author: magic
author_rank: Super Contributor
timestamp: February 09, 2020, 09:03:45 pm
content: Maybe somebody cloned the /2~/8 divider but no one cloned the /20~/80 variant yet

author: wraper
author_rank: Unknown
timestamp: February 09, 2020, 10:17:41 pm
content: Quote from: Miti on February 09, 2020, 08:48:12 pmMight be crappy clone of MC12093. Or you are measuring wrong. Try connecting input to GND and leaving output unconnected.

author: wraper
author_rank: Unknown
timestamp: February 09, 2020, 10:19:11 pm
content: QuoteBecause they sell what sells well at the time. They can literally "make" what was asked. I've once received Toshiba stepper driver IC re-marked as other. Using such would result in guaranteed magic smoke.

author: Leo Bodnar
author_rank: Frequent Contributor
timestamp: February 09, 2020, 10:24:12 pm
content: Does it work all the way to 1.4GHz?Leo

author: Miti
author_rank: Super Contributor
timestamp: February 09, 2020, 11:21:07 pm
content: Quote from: wraper on February 09, 2020, 10:17:41 pmYes, it goes down to 2mA, that's the lowest I can get.

author: Miti
author_rank: Super Contributor
timestamp: February 09, 2020, 11:48:24 pm
content: Quote from: Leo Bodnar on February 09, 2020, 10:24:12 pmThe datasheet looks funny. Shouldn't be Typ 1.1GHz and Max 1.4GHz? Anyway, here are the results for the upper limit of the frequency:Input level Max freq.0+ dBm 2.1GHz-5 dBm 1.8GHz-10 dBm 1.2GHz-15 dBm 1GHz

author: graybeard
author_rank: Frequent Contributor
timestamp: February 11, 2020, 04:31:42 pm
content: It’s done because there is money to be made with counterfeit chips. Check out these videos

author: thm_w
author_rank: Super Contributor
timestamp: February 12, 2020, 01:55:53 am
content: Luckily you didn't get this one, apparently an optocoupler:https://www.aliexpress.com/item/4000118105223.htmlThere is one more source here, with different silkscreen:https://www.aliexpress.com/item/4000358826445.htmlYou can get for sure genuine ones for $1.10 each, but they are salvaged. So, I don't expect prices for new chips to be much less than that.What are you using the chip for?

author: EEEnthusiast
author_rank: Frequent Contributor
timestamp: February 12, 2020, 03:02:52 am
content: I know from first experience on some of the production facility in china for ICs. For e.g. if a semicon fab is making an IC , say for Microchip 93LC46B. If they figure out that the parts are selling in large volumes, they would start an alternate production unit for this. Those units would NOT be delivered to microchip, but to the local market for assembly. When they leave the semicon fab, these ICs would be un-marked, in order to protect IP issues and other legal clauses. Once in the local market, these would be screen printed or laser etched with the part number and Microchip logo. It then ends up in the assembly units when these parts are requested by some one who is assembling a board. Now in this case Microchip does not make any money as the product never comes from Microchip. But the end user does not know it because the parts look and function the same as original.The only problem is when someone in the local market makes a mistake and prints the wrong part number on the blank ICs which came out of the fab. That's what you have got now.

author: Miti
author_rank: Super Contributor
timestamp: February 12, 2020, 04:14:46 am
content: Quote from: thm_w on February 12, 2020, 01:55:53 amI’m working on a tracking generator for my spectrum analyzer. This was supposed to divide the 300MHz calibration output for the ADF4351 30 MHz reference frequency. This way I don’t need to tap into the 10MHz reference of the SA.Anyway, apparently they fully refunded the amount. I’ll have to check my card balance.

author: magic
author_rank: Super Contributor
timestamp: February 12, 2020, 07:48:16 am
content: Quote from: EEEnthusiast on February 12, 2020, 03:02:52 amI doubt that mistakes are the only reason

author: gbaddeley
author_rank: Regular Contributor
timestamp: February 12, 2020, 08:03:31 am
content: Quote from: EEEnthusiast on February 12, 2020, 03:02:52 am"protect IP issues and other legal clauses" What do you mean by this statement? It looks like IP is being stolen from Microchip and remarketed with non-genuine labelling.

author: magic
author_rank: Super Contributor
timestamp: February 12, 2020, 08:07:42 am
content: To protect their ass from getting sued for trademark infringement or NDA violation

author: EEEnthusiast
author_rank: Frequent Contributor
timestamp: February 12, 2020, 08:07:49 am
content: Quote from: gbaddeley on February 12, 2020, 08:03:31 amFor e.g. a worker cannot walk out of the fab with few microchip (or any other company logo) chips and provide it to another vendor. Unmarked chips will create no suspicion when carried and delivered. If caught, then it is very difficult to find out if those parts are smuggled out of the fab. Thus they avoid any legal issue, IP rights etc..

author: EEEnthusiast
author_rank: Frequent Contributor
timestamp: February 12, 2020, 09:28:40 am
content: Quote from: blueskull on February 12, 2020, 08:57:18 amYes, that is possibly the way they can sell the same ICs for cheaper than the original manufacturer or distributor.

author: EEEnthusiast
author_rank: Frequent Contributor
timestamp: February 12, 2020, 09:47:33 am
content: Is LCSC considerably cheaper than Digikey. I do not think so. I was comparing some prices of common ICs and I found it to be similar.

author: wraper
author_rank: Unknown
timestamp: February 12, 2020, 12:11:54 pm
content: Quote from: EEEnthusiast on February 12, 2020, 09:47:33 amYou were comparing wrong things. If you want exact IC part number from western company it won't be cheaper for many things. But you can save a lot on passives, connectors and equivalent parts. I spread my orders between 6 suppliers to get the best price: LCSC, TME, Maritex, Mouser, Farnell, Digikey.

author: gbaddeley
author_rank: Regular Contributor
timestamp: February 13, 2020, 08:58:51 am
content: Quote from: EEEnthusiast on February 12, 2020, 08:07:49 amYou are stating that workers are committing theft and taking measures to avoid getting caught and getting into trouble. I wonder if the major companies for which these chips are being made are aware that this is going on. This activity seems to be quite distinct from legitimate second-sourcing deals that the major company is party. Interesting.

author: EEEnthusiast
author_rank: Frequent Contributor
timestamp: February 15, 2020, 08:24:20 am
content: Quote from: gbaddeley on February 13, 2020, 08:58:51 amI do not think it is the worker initiating and doing this. The contract manufacturing fab managers/owners need to be aware of this. There is not other way for them to get access to the masks needed to build the IC.