[throwup238]

> So what’s going on with the cheap parts? My best guess is that these are either quite good copies, or failed parts that somehow made their way into the hobbyist supply chain.

The vast majority of counterfeit chips I've seen were from ghost shifts but IIRC TI fabs all their analog parts in house, I doubt they're ghost shift parts or failed QC.

I think its probably a relabeled ADS1015.

[q3k]

Interesting, most of the counterfeits that affect me (eg. FTDI, STM32 clones) have been just straight up clones developed from scratch, not excess inventory / ghost shifts / packaged rejects. I guess it might be a digital/mixed-signal split, with the two worlds having different issues?

(also interestingly the STM32 clones I've seen had stacked die flash because they didn't fab them in a technology that could also do flash, so you can easily tell the counterfeit from sanding down the package and looking for an extra set of bonding wires; it's also a cool place to access the internal flash bus if you wanna bypass some readout protection :) )

[throwup238]

I remember the mess with FTDI clones back when I was still a hobbyist and buying stuff from eBay, but ever since I’ve started doing EE professionally I rarely run into anything that bad. You’re not going to make a clone Marvell processor for example, but I’ve run into several ghost shift runs from a distributor.

I don’t usually buy from electronics markets in Shenzhen either so that probably helps.

[londons_explore]

Buy in bulk from the Shenzhen markets and sellers will be pretty clear that you're getting a clone, and will give you samples of that specific clone so you can QA your product with them. (Some popular devices have multiple clone suppliers).

I now always buy clones where possible - whilst not all features are implemented and some specifications won't be met, the devices seem to match the original for reliability, and sometimes even come with their own cloned modded datasheet.

[jamesbowman]

Author here. I did consider this, as others have reported getting ADS1015 marked as ADS1115. If it were an ADS1015 the readout would be truncated at 12 bits. These parts definitely delivered 16 bits of readout.

[hex4def6]

I worry about the demo boards being radically different in terms of layout etc. Even if you're using the same interface and power supply, the PCB may be affecting performance.

Getting full spec performance out of an ADC requires having good layout power supply routing etc.

I would transplant the chips from PCB A to PCB B and vice versa. See if the performance follows the chip or the PCB.

Also check power consumption before / after board swaps. If they are fakes, that would be significantly different.

[londons_explore]

It doesn't take much crosstalk from some clock signal into the signal you're measuring to really mess stuff up...

Many of these Dev boards are not produced with as much care or knowledge as the chip design itself.

[throwup238]

Ah oops I missed that. Maybe an ADX111A then?

[gsmecher]

Oh my - good find, and also, eek.

Analogy: https://datasheet.lcsc.com/lcsc/2302211830_analogysemi-ADX11...

TI: https://www.ti.com/lit/ds/symlink/ads1115.pdf

Analogy's datasheet is directly cribbed from TI's (see TI Fig. 7-7 / Analogy Fig. 22½, pg. 18).

This already passes my "run away screaming" threshold for trust, but a decapping would help me understand whether they've stolen the physical design (bad) or just cloned it (bad).

See also: https://community.element14.com/members-area/f/forum/53365/n...

[kragen]

"Stealing" the physical design is legal after 10 years in the US (https://en.wikipedia.org/wiki/Integrated_circuit_layout_desi...), or 20 years if there's a patent, and that's how we avoided having a single giant company own everything and halt innovation forever in the First and Second Industrial Revolutions. So I would say that stealing the physical design is good.

[kragen]

(I guess it was also important that at the time it was illegal for one company to own another, which was a significant obstacle to the rise of conglomerates like Standard Oil.)

[q3k]

> or just cloned it (bad)

What's wrong with cloning a chip functionality-wise? This is basically how the industry has operated since its infancy, and what gave us jelly bean logic parts and transistors, x86 and the PC revolution, ...

(just talking about the cloning part here, not counterfeit markings or datasheet copyright infringement, or copying mask work)

[mschuster91]

If it's an open clone that can be reasonably distinguished from software side and from looking at the part and it doesn't violate IP laws other than software patents, no biggie.

Every clone of any sufficiently complex Thing will have subtle quirks and edge cases compared to the original and as long as I can work around them for only that specific clone model, that's easy.

But clones that have no way of determining if the part is a clone? That's bad to even exist because unscrupulous actors will go and repackage "legitimate clone" chips into faked originals if the price difference is big enough.

[userbinator]

that can be reasonably distinguished from software side

That defeats the point of it being a clone. 100% the same is the goal.

[gsmecher]

There's nothing wrong with an open clone when everybody is acting in good faith. (In fact, "good faith" does not even necessarily mean "according to the letter of the law in $jurisdiction". Sometimes the law is an ass.)

However, there's nothing more toxic to an OEM than a vendor relationship founded on dishonesty. I know I shouldn't trust them, they know it too, and even if it seems advantageous at first I shouldn't be surprised when they turn on me.

Since these parts are being sold as genuine TI parts, I don't care whether the clone is physically faithful or just functionally faithful - I should treat it like it's poisonous.

[userbinator]

Apparently you haven't seen what the datasheets of 7805 regulators look like; or to use a far more complex example, LCD controllers. I do find it amusing that AnalogySemi's datasheet uses basically the same fonts as Linear Technology's, but copy-paste is the norm in the industry, and many companies will require that parts in their design always have a second-source manufacturer, if not more.

[duskwuff]

I've seen some datasheets which were copy/pasted to the extent that some of the example schematics still used the name of the original part.