Unit 9. MOSFET Current Sources

With the evolution of integrated circuits, it was necessary to reduce the number of resistors in the circuit, and the solution was the transistor current source. An added bonus was that the circuit was generally greatly improved as well. Here, the basic principle is introduced, followed by a discussion of the standard method of increasing the current output resistance with source degeneration. The application of a current-source configuration for balancing a differential amplifier stage is discussed.