| 摘要 |
The unwanted varation in operating point asscoiated with varying gain of a common input/output electrode transistor, such as a common emitter bipolar transistor, is obviated by coupling an electronically controllable conductance in a negative feedback path between a first input/output electrode (collector) and the control electrode (base) of the transistor. A first embodiment applied to a bipolar device, the electronically controlled feedback element comprises a diode, having its forward conductance varied by adjusting current flow through a controllable current source. The controls the amount of feedback from the collector to the base and the forward loop gain of the common emitter transistor. A second embodiment for a bipolar device, the controlled feedback element comprises an emitter-follower transistor, with its forward gain controlled by varying the current drawn through its emitter by a controllable current source/sink. This, in turn, varies the amount of voltage fed back from the collector to the base and thus the gain of the common emitter trasistor. |
