5 ms·

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. Th

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 1y ago
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 1y ago
  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 1y ago
Ah oops I missed that. Maybe an ADX111A then?
- gsmecher 1y ago
  Oh my - good find, and also, eek. Analogy: https://datasheet.lcsc.com/lcsc/2302211830_analogysemi-ADX111AQFN10_C5359372.pdf https://datasheet.lcsc.com/lcsc/2302211830_analogysemi-ADX11... TI: https://www.ti.com/lit/ds/symlink/ads1115.pdf 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/new-clone-on-the-block https://community.element14.com/members-area/f/forum/53365/n...
  - q3k 1y ago
    > 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 1y ago
      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 1y ago
        that can be reasonably distinguished from software side That defeats the point of it being a clone. 100% the same is the goal.
    - gsmecher 1y ago
      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.
  - kragen 1y ago
    "Stealing" the physical design is legal after 10 years in the US (https://en.wikipedia.org/wiki/Integrated_circuit_layout_design_protection#United_States 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.

hex4def6 1y ago

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 1y ago
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 1y ago

Ah oops I missed that. Maybe an ADX111A then?

gsmecher 1y ago
Oh my - good find, and also, eek. Analogy: https://datasheet.lcsc.com/lcsc/2302211830_analogysemi-ADX111AQFN10_C5359372.pdf https://datasheet.lcsc.com/lcsc/2302211830_analogysemi-ADX11... TI: https://www.ti.com/lit/ds/symlink/ads1115.pdf 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/new-clone-on-the-block https://community.element14.com/members-area/f/forum/53365/n...
- q3k 1y ago
  > 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 1y ago
    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 1y ago
      that can be reasonably distinguished from software side That defeats the point of it being a clone. 100% the same is the goal.
  - gsmecher 1y ago
    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.
- kragen 1y ago
  "Stealing" the physical design is legal after 10 years in the US (https://en.wikipedia.org/wiki/Integrated_circuit_layout_design_protection#United_States 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.