An LED driver for controlling a current supplied to an LED fixture, the LED driver including a switched mode power supply (SMPS) for providing the current to the LED array and a control unit for controlling a switch of the SMPS. The control unit includes an input terminal connected to a current sensing circuit and the switch is connected to the LED fixture at a node downstream of the LED fixture. The current sensing circuit of the LED driver provides a feedback signal to the input terminal of the control unit; the current sensing circuit including a current sensor arranged to provide, when the switch is closed, the feedback signal representing a level of the current supplied to the LED fixture; the current sensing circuit further providing the feedback signal indicating a zero-crossing of the current supplied to the LED fixture when the switch is open.