How to trigger 74LS123?

Hi friends:

I got a serious problem with 74LS123.

74LS123 has been configured as following:

1CLR-----VCC
1A-------GND
1CEXT----100PF( one pin is conected to GND )
1REXT----120K
1B-------INPUT
1Q-------OUPUT

Input keeps changing from 1V to 3.5V repeatedly.

Why this chip can not be triggered?

Beg for you help....

Parents
  • Hi friends:

    I got a serious problem with 74LS123.

    74LS123 has been configured as following:

    1CLR-----VCC
    1A-------GND
    1CEXT----100PF( one pin is conected to GND )
    1REXT----120K
    1B-------INPUT
    1Q-------OUPUT

    Input keeps changing from 1V to 3.5V repeatedly ( 25HZ ).

    Why this chip can not be triggered?

    Beg for you help....

Reply
  • Hi friends:

    I got a serious problem with 74LS123.

    74LS123 has been configured as following:

    1CLR-----VCC
    1A-------GND
    1CEXT----100PF( one pin is conected to GND )
    1REXT----120K
    1B-------INPUT
    1Q-------OUPUT

    Input keeps changing from 1V to 3.5V repeatedly ( 25HZ ).

    Why this chip can not be triggered?

    Beg for you help....

Children
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