Data Sheet Query

Discussion in 'Homework Help' started by Andreas, Feb 3, 2009.

  1. Andreas

    Thread Starter AAC Fanatic!

    Jan 26, 2009
    Take for example the very common series of Hex Inverters by Texas Instruments CD4069U, SN74LS04, and Fairchilds own MM74HC04.
    Why is it that on some data sheets manufacturers such as TI refer to particular attributes such as propagtion Delay, transistion Times & Capacitance as either, Dynamic Electrical Characteristics and Switching Characteristics respectively whereas Faichild refer to it as AC Electrical Characteristics. How can that be? After all they are operating under DC test conditions (there is no changing of polarity occuring here).
    AC - why is this and why don't they stick to a convention according to IEEE standard?

  2. beenthere

    Retired Moderator

    Apr 20, 2004
    Probably because most of those devices were made and typed before there was an IEEE standard.
  3. mik3

    Senior Member

    Feb 4, 2008
    On datasheets AC characteristics doesn't mean that you use the devices with AC (alternative current) signals. It means the characteristics (parameters) related to changing signals (varying DC voltages).
  4. Andreas

    Thread Starter AAC Fanatic!

    Jan 26, 2009
    Yes, this much I know through deduction. But you have to admit it is misleading as AC (for the most part, generally) means that the signal's current changes polarity with time. And I guess this is why Manufacturers refer to it as different things - just their artistic license you might call it.