September 8, 2018
AD MAT02 - supermatched BJT - real vs fake : weekend die-shot
LM394 gone first. Manufacturing of MAT02 stopped around 2010. No surprise it is hard to come by a real one from old stock.Modern alternatives for low noise supermatched BJTs are Analog Devices MAT12 and the like.
Genuine one first (both Analog MAT02CH and MAT02EH are the same). Die size 1506x1407 µm. Image matches photo in datasheet.
PMI logo is Precision Monolithics, Inc, which was bought by Analog Devices back in 1990.
Fake ones (both MAT02EH and MAT02AH) looks more like LM394, but with very rough metalization. Die size 1342x1443 µm: