Patent ID: 6441672
Filing Date: 2002-08-27
Classification: H03L

Abstract:
A circuit arrangement for generating a control potential for a field-effect transistor from an output voltage of a filter circuit, in which the output voltage of the filter circuit is passed to a capacitive voltage divider having a tap that carries the control potential, the circuit arrangement comprising:a charge reversal circuit connected to the tap that provides a charge-reversal current at the tap if the filter output voltage deviates from at least one of a fixed upper filter output voltage magnitude and a fixed lower filter output voltage magnitude; and a current branch connected to a filter output node for providing at the node, while the filter output voltage deviates from at least one of the magnitudes, a current that alters the filter output voltage so as to counteract the deviation; wherein a current ratio between the charge-reversal current and the current in the current branch is dimensioned such that a ratio between a current entering or leaving the filter circuit and a change in the control potential at the tap is approximately constant.