The present disclosure relates to a driver circuit for an optical light emitter of a ranging device, the driver circuit comprising: an inductor having a first of its nodes coupled to a current driver; a first branch comprising a first switch coupled between the second node of the inductor and a first supply voltage rail; a second branch for conducting a current through the optical light emitter, the second branch being coupled between the second node of the inductor and the first supply voltage rail; and a current sensor configured to detect the current passing through the inductor and to provide a feedback signal to the current driver.