Experiment 15 - Currents in Darlington and Szikali Pairs

How does the current flow in the different Darlington and Sziklai pairs? Here you compare the circuits.

In order to compare the different circuits, you assume a base current I_B1 = 0,1 μA into the transistor T₁ and a gain β = 200 for all transistors. As a result the following currents flow in the circuits...

The Darlington Pairs

Currents in the Darlington Pair.

Currents in the PNP Darlington Pair.

The Sziklai Pairs

Currents in the Sziklai Pair.

Currents in the PNP Sziklai Pair.

With the knowledge of the currents, you can now easily calculate the gain of the entire circuit...