The Great ADS1115 Pricing and Sourcing Mystery
Following up on the recent test of a set of purported ADS1115 ADCs sourced from Amazon [James Bowman] didn’t just test a genuine Ti part, but also dug into some of the questions that came up after the first article. As expected, the AdaFruit board featuring a presumed genuine Ti ADS1115 part performed very well, even performing significantly better on the tested parameters than the datasheet guarantees.
Thus we can confirm that when you get the genuine Ti part, you can expect very good and reliable performance for your ADC purposes. Which leaves the unaddressed questions about what these cheapo Amazon-sourced ADS1115 ICs are, and how it can be that LCSC has what should be the same parts for so much cheaper than US distributors?
As far as LCSC pricing is concerned, these are likely to be genuine parts, but also the subject of what is known as price discrimination. This involves pricing the same product differently depending on the targeted market segment, with e.g. Digikey customers assumed to be okay with paying more to get the brand name assurance and other assumed perks.
Regarding the cheapo parts off Amazon, these could be QA failed parts, ‘third shift’ or other grey zone parts being sold for less, as well as outright fakes. The Analogy ADX111 for example is basically a drop-in clone of the ADS1115, down to parts of the datasheet, with the heading image showing a section to compare the two. Interestingly, the ADX111 is sold for $1.77 in 1,000 quantities on LCSC.
Ultimately it’s hard to tell the true origin of the ‘ADS1115’ ICs on one of these cheap boards. They could have fallen off a genuine ADS1115 production line, be QA failed ADX111 parts or something else entirely. Without decapping a few samples and further in-depth research we’ll likely never know.
Yet as some already commented, does it truly matter? You get the cheapo parts when you’re just screwing around with a prototype rather than splurging for the gold-plated AdaFruit version, and source from LCSC or Digikey when it’s time for PCBA. In the end everyone is happy, even without knowing whether it’s truly meat a Ti part that we’re using.