VOLTAGE TO CURRENT CONVERTER FOR HIGH FREQUENCY APPLICATIONS

摘要

A voltage-to-current converter having a two-stage direct amplifier (42) with an overall feedback network having an active differential current-to-voltage converter (47). The first stage is a voltage-to-voltage converter (43) receiving an input voltage signal. The second stage is a transconductance amplifier (45) supplying an output current. The output current of the feedback network is applied to a differential amplifier (50) cancelling all DC components and amplifies only the AC components which are fed back to the input. The feedforward gain of the direct amplifier and the feedback gain of the feedback network may be separately adjusted. The differential amplifier includes a local resistive feedback network having local gain determined by resistors which doesn't introduce any non-linear elements. The feedback network gain of the voltaged-to-current converter may be adjusted without affecting the direct amplifier solely by varying the resistive feedback network of the differential amplifier.