Stabilized current generator with single power supply, particularly for

Abstract

A stabilized generator includes an operational amplifier with capacitive negative feedback whose output signal controls a current regulator which drives the input of a current mirror circuit, the mirrored current from the mirror circuit controlling a feedback circuit adapted to drive the operational amplifier in order to maintain the mirrored current constant. The feedback circuit includes: a first capacitor and a first electronic switch, in parallel, with one end at a fixed voltage and the opposite end fed by the mirrored current; a second capacitor with an end at the fixed voltage and the opposite end connected to a second electronic switch adapted to connect the second capacitor to an inverting input of the operational amplifier in a first, inactive, position, and to the free end of the first capacitor in a second, active position, the second electronic switch being controlled synchronously with the first electronic switch by a square-wave clock signal, in such a way that the first electronic switch is alternately open while the second electronic switch is in its active position and closed while the second electronic switch is in its inactive position; furthermore, the non-inverting input of the operational amplifier is connected to a fixed reference voltage source.