Comment by trinsic2

7 hours ago

Jeese. I was not sure which image was the suspect one.

If you've read the docs, which I'm not saying anyone is expected to, FTDI tends to put buffers on their outputs. That's what gave it away for me. The little sot-23-5 footprints.

  • I got it backwards because I expected the counterfeit part to use a newer process IC (less silicon area) than a possibly more reliable and perfectly suitable for serial connection speeds 'vintage' process on some long stable spin of silicon.

    Why allow for newer processes on the counterfeit? They'd implement it using the least expensive, most mass produced chips possible, which are more likely to be cut from wafers hitting the sweet spot of size / feature and price crossover.

the one which looks cheaper to manufacture

which is definitely the second

  • This is how I ID'd it; I have next to zero experience with ICs, but I've opened up a lot of devices for fun or repair and the cheap stuff always has wiring haphazardly contorted like the left side on the counterfeit, like someone had to force it in there and squeeze it shut just to get it out the door.

They gave it away by saying the genuine cable was a 234 series (small basic UART) and not a 232 (big ol' 28-pin chip).

You don't need any specialized knowledge, just pick the one that looks "cleaner" and "neater" than the other.

It's sufficient to look at something as basic as the arrangement of cables on the left. The crooked electrical elements on the right are also a big tell.

This works because good—and bad—qualities correlate with each other.