PNP switching negative voltage

Discussion in 'General Electronics Chat' started by maca_404, May 7, 2011.

  1. maca_404

    Thread Starter New Member

    Nov 1, 2010
    I have a 0/5v square wave and I need to level shift it, I can easily use a pnp transistor and shift it to a 0/12v wave. However I would like to use the same transistor to level shifted the 0/5v wave to -12/0 and no matter which way around I put the setup I cant seen to get it to work. Cant this be done ?. The load on the -12 supply will only be around 1.2ma.
  2. Adjuster

    Well-Known Member

    Dec 26, 2010
    This probably can be done, but more information would help. For instance, how do the input and output correspond?

    5V in to give 0V out suggests common base, but perhaps you want 5V in for -12V out?

    How much current can the original 5V signal source deliver? Have you got a -12V supply?