Help with 74S124 IC

Discussion in 'General Electronics Chat' started by dumindu89, Oct 12, 2012.

  1. dumindu89

    Thread Starter Member

    Oct 28, 2010
    113
    0
    Since there is no typical cct mentioned in the 74S124 datasheet, I implemented the following circuit diagram and observed the output. But there no output shown in the oscilloscope.

    [​IMG]

    What is the wrong with cct? Can anyone help?
     
  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
    2,936
    488
    Connect the enable pin to ground.

    Connect some adjustable voltage source to pin 2 and 3 to choose the range and frequency.

    See figure 2 of the datasheet.
     
    dumindu89 likes this.
  3. ScottWang

    Moderator

    Aug 23, 2012
    4,855
    767
  4. dumindu89

    Thread Starter Member

    Oct 28, 2010
    113
    0
    Hmm. The particular design needs a high voltage.
    I will try the schematic shown above again with the suggestions made by praondevou. Actually I didn't grounded the enable pin.

    I think that it is not a problem to give any voltage to pin 2 and 3 to check the free running frequency.
    If I am wrong let me know.
     
  5. MrChips

    Moderator

    Oct 2, 2009
    12,446
    3,362
    As praondevou says, 1EN' pin-6 must be tied to GND.
    Try 1FC pin-2 at 5V and 1RNG pin-3 at GND.
     
  6. ScottWang

    Moderator

    Aug 23, 2012
    4,855
    767
    The web that I linked has said:
    We can use lower voltage for this, but it means the VCO would be no more wide-range.
    So, it depends on how you use the range.
     
Loading...