OB5617x is a high power factor, low THD, and highly integrated buck regulator with advanced features to provide high efficiency control and high precision constant current output for LED lighting applications.


The proprietary CC control scheme is used and the system can achieve high power factor and low THD. Quasi-resonant (QR) operation and clamping frequency greatly improves the system efficiency. The advanced start-up technology is used to meet the start-up time requirement (<0.5s). The constant output current is compensated for tolerance of transformer inductance variation.


OB5617x offers comprehensive protection coverage with auto-recovery features including LED open loop protection, LED short circuit protection, Line over voltage protection, cycle-by-cycle current limiting, built-in leading edge blanking, etc.



OB5617x is offered in SOP8 package.


n High PF (>0.9)

n Low THD

n High Voltage Power Supply

n High precision constant current regulation at universal AC input

n Fast start-up (<0.5s)

n Low system cost and high efficiency

n Quasi-resonant operation

n Programmable CC regulation

n LED short circuit protection

n LED open loop protection

n Cycle-by-cycle current limiting

n Built-in leading edge blanking (LEB)

n Line fold-back control

n Line over-voltage protection

n Thermal fold-back control



n LED lighting




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