"fetal" newbie ground question

Discussion in 'Homework Help' started by judithson, May 27, 2004.

  1. judithson

    Thread Starter New Member

    May 27, 2004
    i am not a engineering student, i just started "tinkering" about a year ago. normally i get my questions answered by researching aron's diy site, but this question still is unanswered.
    if a circuit has an analog ic, in this case ad633jn, and the schematic shows two pins to ground and shows a pin for -v , besides a pin for +v......
    what's going on?
    does it require ac,
    or does the -v pin go to ground like all my other projects to date?(dc)
    any help and or guidance would be greatly appreciated!

    the project's portion i am speaking of is at:
  2. judithson

    Thread Starter New Member

    May 27, 2004
  3. mozikluv

    AAC Fanatic!

    Jan 22, 2004
    hi judithson,

    pins 2 & 4 are the inverting input of the internal differential amp and 1 & 3 are the non-inverting. normally pins 2 & 4 are connected to ground in the multiplier function, likewise it can be also reversed depending on the function.

    pin 8 is your positive rail supply connection and pin 5 is your negative rail supply connection. the power supply that is used here is dual with a common ground.

    this is a very versatile chip, you can use that as a voltage controlled high/low pass filter, as a frequency double or as modulator or demodulator.

    pin 7 is your output and pin 6 is the summing input

    hope this helps.
  4. judithson

    Thread Starter New Member

    May 27, 2004
    thanks mozikluv!
    is this something that is also known as "bi-polar"?
  5. beenthere

    Retired Moderator

    Apr 20, 2004
    Hi Judithson

    Bipolar is one of those terms that is most meaningful in context. For instance, there are electrolitic capacitors constructes such that there are two in the same can, connected in a way that they can pass AC signals.Rather than non-polar, they are generally called bipolar.

    In the case of your AD633, it is likely constructed using both NPN and PNP transistors. Since the transistors are of different polarities, the device is then bipolar. In the same way, a logic ic can be bipolar if it uses N channel and P channel fet's.