A reference design for LED streetlights, high-bay lights and other high power LED lighting applications has been announced by Power Integrations. RDR-382 describes a constant current, 43V (nominal), 150W reference power supply for 90-265VAC solid-state lighting, utilising the company's HiperPFS-2 PFC controller ICs and HiperLCS integrated LLC power stage ICs.
Rather than using traditional dual-stage drivers with separate PFC and LLC stages produce a constant voltage output requiring multiple DC/DC converters to convert the output to constant current, RDR-382 employs a novel feedback and control scheme which enables the LLC to provide constant current directly at the output. This enables component counts to be cut by approximately one-third, efficiency to be increased to over 93% and reduced size due to the elimination of the DC/DC converter stage.
The high nominal LLC switching frequency of 250kHz reduces the size of the required magnetics, while the use of a continuous-conduction-mode, variable-frequency PFC stage reduces EMI compared to fixed-frequency alternatives.
The reference design can be used to drive single or multiple LED strings and allows analogue dimming to be implemented with a 0-10VDC input.
Andrew Smith, Senior Product Marketing Manager, Power Integrations, comments: “Reliability is especially important for high-power lighting applications above 75W output. Because this design is high efficiency, less heat is generated. In combination with a reduced component count, this ensures a long lifetime.”