Designing an amplifier

Discussion in 'Homework Help' started by Sirius Black, Mar 10, 2012.

  1. Sirius Black

    Thread Starter New Member

    Mar 10, 2012
    My task is to design an amplifier with the following specifications.
    -Open circuit voltage gain of 100 (+-)10%
    -Input resistance greater than 1k ohm
    -Operate on 12v supply
    -Voltage swing of (+-)2.5 volts around q-point

    The design must only use capacitors, resistors, and 2N4401 transistors

    I really have no idea of where to start, and what to do. I have a basic knowledge of circuits and transistors, so if I could get started in the right direction I might be able to design it.

    Thanks in advance
  2. hobbyist

    AAC Fanatic!

    Aug 10, 2008
    Here is how you start a design,

    Look over your list of constraints, and decide what circuit configuration, could achieve this, then choose arbitrarily, what part of the circuit you would like to work on first.

    The input stage or the output stage, from there you start using all the calculations to work out component values.

    Then always prototype the circuit, and measure all your calculated values of bias voltages, and adjust values as needed, then do the dynamic tests on the circuit, to check for performance according to specs.

    If it does not spec out, then back to square one, and start the design from another aspect, from a different part of the circuit.

    You could start with oversall gain, or input impedance, output voltage swing, ect.. the list goes on, but to start a circuit design consists of choosing arbitrarily where you think the design is best started from, that you are most knowledgeable with.

    Hope this helps.