Driver device (50a-50j) for driving a load, in particular an LED unit comprising one or more LEDs, said driver device comprising: - power input terminals (51, 52) for receiving a rectified supply voltage from an external power supply, - power output terminals (53, 54) for providing a drive voltage and/or current for driving a load, - a half-bridge unit comprising a first and a second switching element coupled in series between a high-voltage node and a low-voltage node and having a switch node between said first and said second switching element, - a boost input filter unit comprising a first inductor coupled between said power input terminals (51, 52) and said half-bridge unit, - a buck output filter unit comprising a second inductor coupled between said half-bridge unit and at least one of the power output terminals (53, 54), - an energy storage unit, and - a control unit for controlling said switching elements (60, 61) characterized in that; i) the power output terminals (53, 54), for providing a drive voltage and/or current for driving a load, or the energy storage unit are directly coupled to the high-voltage node and the low-voltage node of the half-bridge unit, or in that; ii) the power output terminals (53, 54), for providing a drive voltage and/or current for driving a load, and the energy storage unit are connected in series between the high-voltage node and the low-voltage node of the half-bridge unit. - power input terminals (51, 52) for receiving a rectified supply voltage from an external power supply, - power output terminals (53, 54) for providing a drive voltage and/or current for driving a load, - a half-bridge unit comprising a first and a second switching element coupled in series between a high-voltage node and a low-voltage node and having a switch node between said first and said second switching element, - a boost input filter unit comprising a first inductor coupled between said power input terminals (51, 52) and said half-bridge unit, - a buck output filter unit comprising a second inductor coupled between said half-bridge unit and at least one of the power output terminals (53, 54), - an energy storage unit, and - a control unit for controlling said switching elements (60, 61) characterized in that; i) the power output terminals (53, 54), for providing a drive voltage and/or current for driving a load, or the energy storage unit are directly coupled to the high-voltage node and the low-voltage node of the half-bridge unit, or in that; ii) the power output terminals (53, 54), for providing a drive voltage and/or current for driving a load, and the energy storage unit are connected in series between the high-voltage node and the low-voltage node of the half-bridge unit. i) the power output terminals (53, 54), for providing a drive voltage and/or current for driving a load, or the energy storage unit are directly coupled to the high-voltage node and the low-voltage node of the half-bridge unit, or in that; ii) the power output terminals (53, 54), for providing a drive voltage and/or current for driving a load, and the energy storage unit are connected in series between the high-voltage node and the low-voltage node of the half-bridge unit.