1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Input and Output Load Lines

  1. Apr 22, 2016 #1
    The problem statement, all variables and given/known data

    I am not sure i know what is meant by the input load line and the output load line in parts b and c. I tried looking it up in my book (fundamentals of microelectronics by razavi) but to no avail. Any help is appreciated.
  2. jcsd
  3. Apr 27, 2016 #2
    Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
  4. Apr 29, 2016 #3


    User Avatar

    Staff: Mentor

    To derive the output load line imagine removing everything from the circuit except the RD and RS resistors, then plotting I vs. V where I is the current in those resistors and V is the voltage across the "empty gap" between them. It is immaterial what element you insert into that gap, the current through it and voltage across it are fully constrained by that pair of resistors together with the supply voltage, and this gap's I vs. V plot is known as the output DC load line.
  5. Apr 29, 2016 #4


    User Avatar

    * Input load line:
    From this: IDS=VG/RS-VGS/RS.
    This gives a straight line crossing the IDS=f(VGS) graph in one point.

    * Output load line
    From this: IDS=(VDD-VDS)/(RD+RS)=VDD/(RD+RS)-VDS/(RD+RS).
    This load line has a negative slope.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted