Electronic – Several variations of the same chip, what does it mean


When I look for ICs online, I often come across a list like this one.

For example, I just searched for the 4N35 optocoupler, and came up with a list:

  • 4N35M
  • 4N35SM
  • 4N35SR2M
  • 4N35SR2VM
  • 4N35SVM
  • 4N35TVM
  • 4N35VM

And this is a relatively short list. Sometimes, differences are obvious (i.e. package type). But the aforementioned are all in DIP package. So is there some sort of a general convention that all manufacturers follow when naming these chips? I mean, how am I supposed to choose which one is right for me? Reading the datasheet searching for a minute difference each and every time can be tedious (sometimes it certainly helps), but I'm wondering if there is a fast way, based on the suffixes of the variants of a component, to tell how it differs from other members in its family.

Best Answer

No standard convention between manufacturers, or sometimes within a single manufacturer.

The different part numbers can refer to:

  • IC Package
  • IC Temperature Rating (Standard, Automobile, Military, Space, etc)
  • Shipping Package (Single, Reel, etc)
  • Voltage Options (i.e. 3v, 3.3v, 5v)
  • Accuracy/Tolerance Options (i.e. 10% vs 5%)
  • Lead Length
  • Lead free or not
  • Speciality options

And so many more, in any combination.