When simulating the Spice-file below (a common emittor amplifier), I noticed that betaac determined by means of the voltage sources vmeasc and vmeasb differs from betaac which is shown in the operating point information: betaac=i(vmeasc)/i(vmeasb)=2.405e-2/7877e-05=305.319 whereas betaac from the operating point information = 332.486
can anyone here explain this?
CEC-amplifier VCC 5 0 DC 10 RB 5 3 680K RC 5 6 1K RG 1 2 10K Q1 7 4 0 BC547B C1 2 3 100u VIN 1 0 AC 1 VMEASB 3 4 DC 0 VMEASC 6 7 DC 0 .AC lin 1 1k 1k .PRINT AC i(vmeasb) i(vmeasc) .PLOT AC i(vmeasb) i(vmeasc) .op
*DATABOOK PHILIPS .MODEL BC547B NPN (BF=530 NE=1.3 ISE=9.72F IKF=80M IS=20F VAF=50V- BR=10 NC=2 ISC=47P IKR=12M VAR=10
- RB=280 RE=1 RC=40 TR=.3U
- CJE=12P VJE=.48 MJE=0.5 CJC=6P VJC=.7 MJC=.33 TF=.5N) .END