Amplifier stage for video signals - has impedance transforming transistor and transistor switch providing clamping

摘要

The main amplifier stage, for video signals, consists of three transistors. The amplified signal is clamped to a given reference. The pre-amplifier stage has a transistor acting as impedance transformer connected by its base via a coupling capacitor to the signal input and by its collector to another transistor acting as a switch. This switch receives control signals. The emitters of the two pre-amplifier transistors are connected to the main amplifier's transistors.