Lab5 Prelab

• The prelab report should be segmented in 2 parts:
  • BJT (Bipolar Junction Transistor)
  • JFET (Junction Field Effect Transistor)\

   

• 1)BJT:
  • from preparation:
    • show PSpice circuit schematic of inverter circuit with BJT (Q2N3904) from figure 5-5 but use only current input Ib to B gate, run a primary DC sweep for Vcc (0 to 10V) and secondary sweep for Ib (0 to 100uA), plot VI curve (Vc-Ve x-axis & Ic y-axis).
    • run a new DC sweep (primary and secondary) of the above circuit after changing Rc value from 1K to 2K, plot VI curve similarly and trace on the same graph the load line equation 5-2, show on the plot where the three different regions, give the ranges for the base current for each region.
    • calculate Rb from ib=(Vin-Vf)/Rb (Vf=0.6V) to make transistor work in the digital regime when 0-5V square wave is applied as input to inverter.
    • calculate Rb from ib=(Vin-Vf-Ic Rc)/(Rb+Rc) (Vf=0.6V, Rc=2k not 1k, and obtain ic from VI curve for Vce=7V) to make transistor work in the linear regime when 0-5V square wave is applied as input to voltage follower.
    •  for both BJT circuits run primary DC sweep for Vin (0-5V) using the computed Rb values, plot input output characteristic curve and identify the three regions.
    • run transient analysis with square wave input (0-5V), plot Vout, show on and off levels.

• 2)JFET:
  • from preparation:
    • show PSpice circuit schematic of inverter circuit with JFET (J2N3819) from figure 5-10, run a primary DC sweep for Vdd (0 to 10V) and secondary sweep for VGS (-2.5 to 0V), plot VI curve (Vd x-axis & Id y-axis).
    • run a new DC sweep (primary and secondary) of the above circuit after changing Rc value from 1K to 2K, plot VI curve similarly and trace on the same graph the load line equation 5-5, show on the plot where the three different regions, give the ranges for the gate-source voltage for each region.
    • plot the input output voltage characteristic, show the three different regions.
    • run transient analysis with square wave input (-5V-0V), plot Vout, show on and off levels.

EE3111                    Courses                    Home Page