Counterfeit F103s

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csnol
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Re: Counterfeit F103s

Post by csnol » Tue Sep 05, 2017 4:18 am

I'm living in China. and bought more than 100 pieces STM32 chips from over 3 sellers. and Chinese forum, never found faked chips.
But you will get used STM32 chips if you wanna pay lower price. The sellers must told you that the chips are used or refurbished chips.
( Free refund in 7 days on Taobao.com)

BTW, It is only US$0.9 dollar in China. Fake it isn't good idea on business I think.

and I never noticed flash size of this chip. It is more enough for me. :D

http://www.stmcu.org/module/forum/threa ... 1-1-1.html

he said stm32f103c8 flash size up to 0x0801FFFF, and readable and writeable.

victor_pv
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Re: Counterfeit F103s

Post by victor_pv » Tue Sep 05, 2017 4:56 am

Fitch wrote:
Tue Sep 05, 2017 12:41 am
Guys,
I understand that a chip sold as 64K that reports 128K is not by itself indication of a fake. My issue were parts clearly marked STM32F103CBT6 that read only 64K. Note, I just read the flash size register I did not try to test the flash for size.

But thinking about it, I am sure the flash size register is programmable by ST, and I would suspect even if they use the same die that they would program it to be the size of the part they mark rather than program it larger. So maybe reading the wrong flash size either more or less is indication of a counterfeit? Just thinking out loud.
If you say counterfeit with the meaning that the part number may have been scrubbed and a new one printed, then perhaps, still this things are so cheap it's hard to believe there is profit left on doing that. If you are meaning that someone cloned the MCU, it doesn't seem like the case so far since STM would have already have heard of them.
Another posibility is that hose are rejects from the factory, perhaps precisely because they were marked with a capacity but programmed to report another, and some way they made it out to the market.
But I do believe they are all STM parts, most likely when the same die, 128KB actual flash, and just the wrong programed size vs label.

dannyf
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Re: Counterfeit F103s

Post by dannyf » Tue Sep 05, 2017 10:14 am

So maybe reading the wrong flash size either more or less is indication of a counterfeit?
looks like "you suspect that they are fakes". that's quite different from "they are fakes".

most of us simply don't have the know-how or the hardware to identify fake chips, especially mcus. the lucky few so far have not been able to say how they identify fake mcus with such a high degree of confidence, unfortunately.
BTW, It is only US$0.9 dollar in China. Fake it isn't good idea on business I think.
here you have the answer as to how / why those stm32f103 boards are so much cheaper than the bare chips you can buy off digikey or arrow, :)

Fitch
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Re: Counterfeit F103s

Post by Fitch » Tue Sep 05, 2017 12:37 pm

Thank you all for your replies. I originally had hoped that someone knew how to identify a fake chip, maybe a font or logo wasn't right, maybe the package is a bit off. Anyway, perhaps all these chips a real, but they are retested from rejected parts? It would explain why you can buy a board with a chip on it shipped from China for less than the 1000 piece price from a US distributor. Might also explain flash size registers with incorrect or bogus data in them.

Anyone find anything else odd about their blue pills or Maple Minis aside from flash size?

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RogerClark
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Re: Counterfeit F103s

Post by RogerClark » Tue Sep 05, 2017 9:24 pm

I dont think low price from companies in China equates to fake parts.

These companies often buy their parts in 1000+ quantities and you are not paying the shipping costs, plus warehousing , plus operating cost of a company in America

dannyf
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Re: Counterfeit F103s

Post by dannyf » Tue Sep 05, 2017 10:17 pm


but they are retested from rejected parts?
Or those parts are real but just someone has figured out a more efficient way to compete, or is willing to accept a lower margin? Or .....

Why do fake parts have to be the only plausible explanation?

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RogerClark
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Re: Counterfeit F103s

Post by RogerClark » Tue Sep 05, 2017 10:31 pm

I'm moving this to Off Topic, as really its a discussion for an official STM site, as it has no appreciable impact on using Arduino on the STM32 series of MCU's

Fitch
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Re: Counterfeit F103s

Post by Fitch » Sat Sep 23, 2017 11:21 pm

Just in case anyone is interested, I purchased some STM32F103CBT6 parts from Arrow Electronics and from EBay seller polida2008. The Arrow price was almost $6, the EBay price was $1.90. I built a test fixture with a socket so I could verify them before soldering them in to anything, and all appear to be the genuine article. My hat goes off to the EBay seller, $1.90 is better than buying a whole reel in the US.

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RogerClark
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Re: Counterfeit F103s

Post by RogerClark » Sat Sep 23, 2017 11:30 pm

Fitch wrote:
Sat Sep 23, 2017 11:21 pm
Just in case anyone is interested, I purchased some STM32F103CBT6 parts from Arrow Electronics and from EBay seller polida2008. The Arrow price was almost $6, the EBay price was $1.90. I built a test fixture with a socket so I could verify them before soldering them in to anything, and all appear to be the genuine article. My hat goes off to the EBay seller, $1.90 is better than buying a whole reel in the US.
@fitch

This is the consensus...

There do not appear to be any cloned or counterfeit STM32s..

Chinese companies can currently source and supply components at costs far below vendors in the USA, Europe etc etc

Whether of not this supply dries up over time, still remains to be seen. But you may as well take advantage of it until that happens ;-)

dannyf
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Re: Counterfeit F103s

Post by dannyf » Sun Sep 24, 2017 12:24 am

counterfeit chips are like compiler bugs: they are incredibly easy for newbies to spot.

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