Nordic NRF24L01+ - real vs fake : weekend die-shot

Resume:

Nordic NRF24L01+ (NRF24L01P) is a very popular 2.4Ghz transceiver used in countless consumer products. Not surprising that we've came across it's fake.This chip was extracted from "expensive" (~10$) RF module with additional RF amplifier chip:Die size - 1876x1761 µm, 250nm technology.Nordic logo on the die:This chip was extracted from "cheap" RF module (<1$):Die size - 2014x1966 µm, 350nm technology.Chip marking is similar, though not identical (genuine one on the right):Fake chip has quite thin marking. Also, text jumps significantly from chip to chip (point stays in place).Despite there were no functional differences reported (yet), one could expect that 350nm compatible chip will have slightly higher power consumption and slightly lower sensitivity. If only this chip was marked properly (Like SI24R1 - one of compatible chips) as compatible - that would have been totally legitimate business. But currently designers, manufacturers and end users are mis-leaded.