Bipolar Transistor Question

Discussion in 'Homework Help' started by andrewmul, May 7, 2007.

  1. andrewmul

    Thread Starter New Member

    May 7, 2007
    Hi, so i'm stuck on this question, tis the first time i've attempted one like this. From reading I thinking its referring to a common-collector amplifier circuit but other than that I am stuck on what to do, any help will be greatly appreciated

    Design the bias circuit for a bipolar amplifier operating from a supply voltage of 10 V, with a collector current of 1 mA at 300 K. Assume the transistor forward gain b = 200 and its reverse saturation current of the ideal emitter-base diode is 0.1 pA.

    a) Find its voltage gain in dBs when driving a load resistance of 1 kOhm.
    b) How would the design be affected if the forward gain beta was only 160 ?
    c) Redesign the bias circuit to improve the sensitivity of circuit performance to variation in b, and quantify the improvement.
    [6 marks ]

    I have spent the last 2 hours reading up on transistors. I worked out the base current from the equation beta = Ic/Ib
    then as i know Rload I drew out the circuit for a common collector amplifier circuit, then i kind of confused myself In working out the voltage gain and wasnt sure whether 0db was the right answer. Also i was not sure about waht the reverse saturation what part that plays. Im using a NPN transistor in the circuit