Investigating Emitter Current Dependence On Temperature 

** Circuit Description **
* power supply
Vcc 1 0 DC +12V
* amplifier circuit
Q1 2 3 4 Q2N2222A
* resistive biasing network accounting for temperature dependence
Rc 1 2 4k TC=1200u
R1 1 3 80k TC=1200u
R2 3 0 40k TC=1200u
Re 4 5 3.3k TC=1200u
Vemitter 5 0 0
* transistor model statement for the 2N2222A
.model Q2N2222A NPN (Is=14.34f Xti=3 Eg=1.11 Vaf=74.03 Bf=255.9 Ne=1.307
+                    Ise=14.34f Ikf=.2847 Xtb=1.5 Br=6.092 Nc=2 Isc=0 Ikr=0 Rc=1
+                    Cjc=7.306p Mjc=.3416 Vjc=.75 Fc=.5 Cje=22.01p Mje=.377 Vje=.75
+                    Tr=46.91n Tf=411.1p Itf=.6 Vtf=1.7 Xtf=3 Rb=10)
** Analysis Requests **
* vary temperature of circuit beginning at 0C to 125C in temperature steps of 25C 
.DC TEMP 0 125 25
** Output Requests **
.PLOT DC I(Vemitter)
.probe
.end