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Chip Sheet Data

Discussion in 'Datasheets, Manuals and Component Identification' started by tedstruk, Jul 17, 2017.

  1. tedstruk

    tedstruk

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    in electronics there is so much BS...(probably why you put up with me) but besides that point, I found a chip that is a 7414, and I assumed it was one of the infamous 74 chips, but after I got the datasheet, it was a pack of schmidt triggers. The chip fires has 6 nand gates and is called a hex schmidt trigger. this may look like a 74 TTL but it isn't. I can't use it for TTL on my eprom.

    Just saying...
     
  2. kellys_eye

    kellys_eye

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    Yes it is a TTL chip. It's a HEX inverter - six basic NOT gates. And, yes, you can use it on your EPROM.

    What do you want to use it FOR?
     
    davenn likes this.
  3. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Jan 21, 2010
    You buy a 7414 and get a 7414. What were you expecting?

    If you want NAND gates, why not buy then. A 7400 sounds like what you want.
     
  4. AnalogKid

    AnalogKid

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    The 7404 is the original TTL hex inverter. The 7414 came later as the first Schmitt Trigger input TTL part. It is drop-in compatible with the 7404. The Schmitt input does not affect how it handles normal edge speed TTL signals.

    https://en.wikipedia.org/wiki/Schmitt_trigger

    Suggestion #1: Read the datasheet *before* ordering a part.

    Suggestion #2: You might want to think a little longer next time before spewing bs about bs.

    ak
     
    OBW0549, (*steve*) and Harald Kapp like this.
  5. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    That's the whole point. We have no idea what you're saying.

    I end up deleting a lot of your posts because they're just nonsense. I thought I may have answered your question (assuming there was one), but each time I read it I'm sure I know less.
     
  6. tedstruk

    tedstruk

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    Jan 7, 2012
    The eprom requires ttl signal at the inputs, I want to trigger the individual registers on the eprom with it.
     
  7. tedstruk

    tedstruk

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    Jan 7, 2012
    Transistor Transistor Logic is new to me...
    Sounds like the base of electronic communication
     
  8. AnalogKid

    AnalogKid

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    Communication, computing, industrial controls, medical devices, spacecraft, consumer devices, whatever. TTL broke the link between one area of electronic circuit design and a traditional college degree in Electrical Engineering. Within a defined set of rules, TTL was a lot like LEGO blocks - you assembled a bunch of them to make something. With TTL, a huge group of people who understood logic but not electrons could design stuff that actually worked. That universal platform supported development of the microprocessor and all that followed.

    TTL was the third logic family to be developed, and the first to achieve truly international standardization and acceptance. Some of the original TTL parts still are in production, but original TTL has mostly been replaced by later, more advanced versions (Shottkey, Advanced, Advanced Shottkey, Bus, etc.) and the many many CMOS families. Basically, almost anything that runs on +5 V will interface with EPROMs.

    ak
     
  9. Harald Kapp

    Harald Kapp Moderator Moderator

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    TTL is just a definition of logic levels.

    This is completely independent from logic functions or logic gates. You can realize the same logic function using different logic families with different logic levels (TTL, CMOS, ECL, ...). Here's the link to our ressource on logic gates.

    When you want to access an EPROM (as in your example), you need to create the required logic to provide address signals and the well-timed control signals (e.g. CS, R/W). When your EPROM requires TTL level sigals, then your signal generating logic needs to generate TTL signals. This does not necessarily mean it needs to be TTL. CMOS, too, can generate TTL logic level compatible signals.

    What do you mean by triggering registers within an EPROM? Do you have a basic understanding how an EPROM works? There are no triggerable register within (at least not the last time I looked inta an EPROM datasheet). You provide an address and control signals and then you can read from the EPROM.
    To write to an EPROM you will need other control signals plus typically a much higher programming voltage.
    To erase an EPROM you use an ultraviolet light source - that's what the window on top of the EPROM is for.

    I agree with Steve's post #5: You're poking around many areas in electronics without showing basic knowledge. What is your general aim? Do you have a specific goal? Are you working along the lines of a textbook to learn?
    I recommend you study a good introductory textbook, We have a collection of book reviews which may help you find a suitable one.

    I do not want to disencourage you. We're here to help everyone from beginner to expert. What we expect is respect for the other members of this forum. Some of your posts border on trolling when they show not the least fundamental work on your side in trying to understand the foundations of what the discussion is about.
     
  10. tedstruk

    tedstruk

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    IMG_20170719_185615171.jpg I really think my hobby is getting a good education from you guys!
    I still don't really understand how TTL with multi-emitter transistors can be simulated or emulated by hex schmitt triggers.

    I had to solder one of the pins that were broke back on...
    look closely at the chips lower left end. there is an indentation on the left end, but there is a second indentation on the lower left end, a round depression. the datasheet I have doesn't kimosabe. What is this chip? please?
     
  11. davenn

    davenn Moderator

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    pin 1 ID

    Kellys eye told you want it was in post #2 ---- go and read it again
     
  12. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Think of TTL as a standard for logic circuits the same way that SAE is a standard for threads on bolts.

    You don't ask how a particular thing which has a thread simulates or emulates the SAE standard.

    What you do see is that the threads on the things comply with SAE and you can connect them to other things which have SAE threads.

    In the same way TTL only describes the input and output characteristics (and the power supply) to allow things which comply with that standards to be connected together.

    Going back to SAE, my thing might be a car steering wheel (which requires a bolt with an SAE thread), or an aircraft window. These are totally different things, and the only thing they might have in common is that you might be able to connect them together with a bolt having a thread common to them (and the result may not be useful -- normally you would pick things that go together and ensure they have compatible fixings).

    The same thing applies to a chip which implements a function. You pick the function and then choose the chip with the required interface.

    In your case, a hex Schmitt trigger (get the name right) is a logic function implemented with a particular interface, specifically a TTL interface in the case of the 7414. This may involve transistors with multiple emitters (and probably does in that dinosaur chip), but it doesn't have to.
     
    Last edited: Jul 20, 2017
  13. Harald Kapp

    Harald Kapp Moderator Moderator

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    Sorry Steve, it really is Schmitt-Trigger

    Schmitt-Trigger is not a logic function. It describes the behavior of a logic circuit whre the input has two thresholds: an upper threshold to detect logic high when the input voltage rises above this threshold and a lower threshold to detect low when the input voltage falls below this threshold. The voltage difference between high threshold and low threshold is called hysteresis. This feature is useful (and used) to restore clear digital signals from noisy inputs or inputs which have slow slopes (when it takes long to change from high to low and vice versa. The Schmitt-Trigger feature is described here.
    In theory one could make any logic function with Schmitt-trigger characteristic. For practical purposes (it takes more transistors, more chip space and is slower) only a selected set of chips is equipped with this feature.

    In this case the 7414 has 6 inverter gates (hex inverter) with Schmitt-trigger input characteristic. This is functionally the same chip as a 7404 (which is also a Hex inverter but doesn't have the Schmitt-trigger characteristic). But this has been said (written) before.
     
    (*steve*) and davenn like this.
  14. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Aaaaagh, I know. Bloody autocorrect.
     
  15. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Yeah, it defines behaviour where the standard definition for the logic family leaves it indeterminate.
     
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