Analog/Digital Dimmable Power Factor Corrected Quasi-Resonant Primary Side Current-Mode Controller for LED Lighting

The NCL30086BH is a controller targeting isolated andnon−isolated “smart−dimmable” constant−current LED drivers.Designed to support flyback, buck−boost, and SEPIC topologies, itsproprietary current−control algorithm provides near−unity powerfactor and tightly regulates a constant LED current from the primaryside, thus eliminating the need for a secondary−side feedback circuitryor an optocoupler.Housed in the SOIC10 which has the same body size as a standardSOIC8, the NCL30086BH is specifically intended for very compactspace−efficient designs. The device is highly integrated with aminimum number of external components. A robust suite of safetyprotections is built in to simplify the design. To ensure reliableoperation at elevated temperatures, a user configurable currentfoldback circuit is also provided. In addition, it supports analog andPWM dimming with a dedicated dimming input intended to controlthe average LED current.Pin−to−pin compatible to the NCL30086, the NCL30086BHprovides the same benefits with in addition, an increased resolution ofthe digital current−control algorithm for a 75% reduction in the LEDcurrent quantization ripple.