Electronic – the purpose of the NLSF457 from On-Semi

circuit-designintegrated-circuit

I was browsing On-Semi just looking around when I ran across the NLS457.
I hit Google and Bing and after trying multiple search terms have came up with 0 hits would answer my question.

The weird part is that I can not find anything even mentioning it, wither at On-Semi or via search engines. I can't believe that they would go through efforts to design, make and sell a chip that has no purpose. It's a new chip(2018) in a small package and so might be useful in a modern device of some kind, I just don't have a clue what it could be.

It takes the output of two AND gates, each of which has an inverted input and feeds it to an OR gate. It looks like something that might clock related, but in that case I would have thought Schmidt trigger inputs would have helped it's usefulness.

It's most likely something real obvious, but all of my schooling was over 25 years ago, most of which was not working in electronics. I'm getting the feeling that I'm going to be feeling rather stupid after it is pointed out to me.

Best Answer

First of all, never feel stupid because you don't know what a component is used for. Most components are actually pretty fairly specific.

Looking through the speeds in that datasheet: it's unlikely this is modern technology. Feels like 1980's "low-voltage high speed logic", like 74LVCxxx.

  • It's quite possible a high-volume customer came to ON Semi (or whatever they were called at the time) and said, hey,

    I've got this device all built up, and it's been certified for all this stuff, but now in the final pre-production tests we figured out that our interrupt pin shouldn't just be an OR of all inputs, but this complex function. Recertifying after complex modification will kill our DoD contract soooooo could you build that logic for us?
    We'll by a million of them, but you need to guarantee that there's capacity for another million.

And then ON Semi went on and produced 2 million and sold them for $10 a piece. Now, they're sitting on the remainder and decided to sell them as product.

  • Or, that's a part to some old digital bus that's been lost to time ("If BUS 1 TRANSMIT READY is high and BUS 1 RECEIVE READY is high OR BUS 2..."); maybe some bus arbiter, or maybe just a "OR" gate operating on differential lines.
  • Or, that's really just a kind of "oring" multiplexer: with input B and D a microcontroller can select which inputs get ORed into the output
  • Or, this is an ancient "all in one" logical gate, where external connection to high or low or actual inputs makes the gate useful.
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