An apparatus for a first current sensor for a switching converter has an inductor and a first switch. The first switch is arranged to selectively couple the inductor to a first voltage. The first current sensor generates a first output current that is dependent on an inductor current flowing through the inductor The first current sensor compensates for an error arising due to the first switch in the generation of the first output current. The apparatus provides an improved current sensor for a switching converter that overcomes or mitigates the problem of errors in the measurement of a current.