The mysteries of the 4089 frequency multiplier

Discussion in 'General Electronics Chat' started by JingleJoe, Jan 22, 2012.

  1. JingleJoe

    Thread Starter Member

    Jul 23, 2011
    I spent a long time last night googling this chip but can't find out what certain pins do :( Specifically pins 1, 4, 7, 10 and 11.
    I feel like I might have missed something obivous, check the datasheet(s) if you wish;
    I understand the operation of the chip and most of the pins but the function of the "15" and "set to 15" elude me.
    Why is there both an inhibit input and output? Does one inhibit the input and one the output? (that seems totally arbitrary to me) Does the inhibit out, output a pulse or something when the inhibit in is active?
    I don't intend to cascade these multipliers so should the cascade input be low for normal operation?
    Does the strobe pin basically turn the output on or off?

    It's those "set to 15" and "15" pins which really confuse me ...
  2. mik3

    Senior Member

    Feb 4, 2008
    Have a look on the truth table on page 3-213 of the datasheet.
  3. JingleJoe

    Thread Starter Member

    Jul 23, 2011
    Oh how did I overlook that? :rolleyes: Thankyou, that helps quite a bit however the "15" and "set 15" pins don't seem to do much o_O ... I suppose this just means I will have to experiment }:¬D mwahahaha