Above are two FTDI FT232RL chips, an extremely common chip used to add a USB serial port to projects, builds, and products. The one on the left is a genuine part, while the chip on the right was purchased from a shady supplier and won’t work with the current FTDI drivers. Can you tell the difference?
[Zeptobars], the folks behind those great die shots of various ICs took a look at both versions of the FT232 and the differences are staggering. Compared to the real chip, the fake chip has two types of SRAM etched in the silicon – evidence this chip was pieced together from different layouts.
The conclusion [Zeptobars] reached indicated the fake chip is really just a microcontroller made protocol compatable with the addition of a mask ROM. If you’re wondering if the FTDI chips in your part drawers are genuine, the real chips have laser engraved markings, while the clone markings are usually printed.