A supply circuit (1) comprising an inductor (2) coupled to switching means (7) and comprising a capacitor (4) is provided with an impedance (3) located between the inductor (2) and the capacitor (4), with a current injector (5) and with a feedback loop comprising a converter (6) for controlling the current injector (5) for compensating a ripple in an output voltage across the capacitor (4). The impedance (3) allows injection of a compensating current at a location different from an output location. This increases a number of possible detections of ripples in the output voltage and allows a ripple in an output voltage to be detected even in case of loads introducing much noise across the capacitor (4). The converter (6) detects a detection signal via the impedance (3) by measuring a voltage across the impedance (3) or across a serial circuit comprising the impedance (3) and the capacitor (4). The impedance (3) comprises a resistor or a further inductor.