Over a year ago I had, in my infinite wisdom, bought 10 pieces of DIP chips from Aliexpress that boldly claim to be TI NE5534 all with the same date/batch code. So I did what any curious and sensible person would do:
measured the slew rate boiled it in acid and extracted the die.
I took a terrible picture using my phone's camera and a salvaged lens from my parts box. Unfortunately I was unable to find a die image of a real 5534.
Zeptobars has an NE5532 image, but that doesn't help me much, does it?
So far I have 3 hints that point to this chip being a fake:
- Same date/batch code on all chips
- The die is absolutely tiny. Longest dimension is at most a milimeter. For comparison, Zeptobars says the TI NE5532 has a die size over 2mm x 2mm.
- The silicon is a bit too simplistic..? I would expect a more complicated circuit, but take this with a grain of salt, I have very little clue.
Any ideas?