Topic: New Primary Side Regulation Constant Voltage Solution in LED Driver

A new primary side regulation constant voltage (PSR-CV) two-stage solution is proposed in this paper to avoid low frequency current ripple and to maintain high power factor, low cost compared with currently single stage and conventional three-stage solution in analog LED dimming or non-dimming application. PSR-CV is employed in primary side to achieve high power factor, simple circuit combined with secondary DCDC stage to eliminate low frequency current ripple and implement dimming function. Furthermore, system cost is reduced due to no need secondary voltage or currentsense circuit, opto-coupler and low voltage stress component in secondary side. Moreover, PSR-CC (constant current) and PSR-CV two-stage solution are contrastive analyzed. Finally, one prototype is built based on PSR-CV and tested to verify the effectiveness of the presented LED driver.