Manufactured and developed by Allegro MicroSystems' subsidiary Sanken Electric, the LC5540LD/LF single-stage, power-factor-corrected, off-line LED driver integrated circuit (IC) series has robust functions within these single-stage converters that have been developed to simplify system designs. The LC5540LD/LF series is suitable for the consumer and industrial markets targeting indoor and outdoor LED lighting and off-line LED lighting applications. Designed for input capacitorless applications that make it possible for systems to comply with the harmonics standard (IEC61000-3-2 class C), the series are quasi-resonant-topology, switching-power-supply ICs and incorporate separate controller and power metal-oxide-semiconductor field-effect-transistor chips. The controller adapts the average current control method for realizing high power factors, and the quasi-resonant topology contributes to the high efficiency and low electromagnetic interference.