I constructed in multisim a common emitter circuit from the following diagram
where the lower Keithley is used to supply VBE and the upper Keithley is used to supply VCE.
I obtained the IC- VCE characteristic curves using the following setting:
- VCE = 0 V to 4 V in 0.1 V steps with 0.1 A compliance.
- IB = 10 μA to 60 μA in 10 μA steps with 15 V compliance.
and then I stored the values of Ic and the forward DC current gain (hFE) for each IB when Vce equal to 1, 2, 3 and 4V.
Basically I filled a table like this:
I'm trying now to calculate the output conductance G.
I know that the definition is
G = ΔIC/ΔVCE with IB at a constant current.
I need to fill the following table
I'm trying to calculate it but I'm not sure if what I'm doing is correct.
For example, considering the results I get for the output characteristic when Ib =10μA
and trying to calculate G for Vce3,Vce1 and Vce4,Vce2:
- The ΔIC = Ic(Vce3) - Ic (Vce1) = 0.55536 - 0.54343 = 0.01193
- The ΔVCE = Vce3 - Vce1 = 3 - 1 = 2
G = 0.01193/2 = 0.005965
And if I do the same thing for Vce4,Vce2:
- The ΔIC = Ic(Vce4) - Ic (Vce2) = 0.56133 - 0.5494 = 0.01193
- The ΔVCE = Vce4 - Vce2 = 4 - 2 = 2
G = 0.01193/2 = 0.005965
I get exactly the same result. Is this correct? thank you in advance.