bilateral switch

Discussion in 'General Electronics Chat' started by blue6x, Apr 26, 2005.

  1. blue6x

    Thread Starter Active Member

    Apr 6, 2005
    i am currently looking on this bilateral switch, the famous 4066...

    i've read that it is capable of squelching or i would rejecting noise if an analog signal is applied in the input. and it says that the input must be in the rnge of the Vcc, normally 5 Volts.

    i would like to know how it process the unnecessary input (analog signal), and up to what range that it ccpet a good input signal.

    The input actually comes from a capacitor which is connected to a phototransistor.
    nother resistor is connected in parallel to the capacitor nd directly connected to the ground...
    The problem of course lies on the light that is being fed on the phototransistor. It could probably accept signal from different light source that is why the switch 4066 is in placed. i would like to know additionl facts on how to process this unwanted signal passing tru 4066..

  2. pebe

    AAC Fanatic!

    Oct 11, 2004
    It doesn't 'process' an analogue signal, if by that you mean filtering it in some way - it's just a switch.

    Imagine the two in/out leads are the same as the two poles of a switch, and the control pin is your finger on the toggle. When you put the control pin high to Vdd, the two in/out pins are effectively connected with an 80Ω resistor. When the control is taken to Vss the path goes open circuit.

    Note that the voltages on the in/out pins must always lie between Vss and Vdd, and there is a current limit on the switch.

    They can be used to switch quite low levels without introducing noise. I have used them to switch the outputs of electret mics.
  3. blue6x

    Thread Starter Active Member

    Apr 6, 2005
    thanks. i thought really thought that somehow, somewhere it is affecting signals on some point. now i know. thanks again.