ABSTRACT
The bipolar transistor is the most commonly used discrete active device. It has the highest transconductance among all transistors. Therefore, it can drive a reactive load with very high frequencies. The MOS transistor has a high switching speed only in integrated circuits, where parasitic capacitances are very small. The bipolar transistor also has some disadvantages. It requires a large area on the surface of integrated circuits. It has a relatively small input impedance and the switching speed is very much limited by the storage time of injected minority carriers.
