High Freq. response of CE amplifier

Discussion in 'Homework Help' started by anik321, Nov 18, 2008.

  1. anik321

    Thread Starter Member

    Oct 25, 2008
    I am designing a two stage CE amplifier followed by a common collector/emitter follower.

    The bandwidth spec is 10hz to 10khz.

    I know all the coupling caps, Emitter caps and input caps all act as high pass filters and thus set the low frequency cut off.

    Where do a put a Low pass filter in this circuit and how do I calculate the highfrequency cutoff for it?.

    The emitter follower is directly coupled to the output of the second CE stage. I am thinking a capacitor from this output (or the input of the CC) to ground would do the trick - but what resistance do i use to set the time constant?

    Any help would be appreciated. Thank you.
  2. Audioguru


    Dec 20, 2007
    Modern little transistors have a frequency response up to 300MHz when the gain becomes zero.
    Depending on how much negative feedback you use then if the stray wiring capacitance of your circuit is low then a flat response up to 1MHz is reasonable.