LYT3316D-TL

Power Integrations LYTSwitch-3 Single-Stage LED Driver ICs are ideal for single-stage power factor corrected constant current LED bulbs and downlighters. The LYTSwitch-3 family supports design flexibility with a buck, buck-boost, tapped buck-boost, boost, isolated and non-isolated flyback up to 20W output. The ICs incorporate a high-voltage power MOSFET, discontinuous mode and variable frequency on-time controller. The controller provides cycle-by-cycle current limit, output OVP, line overvoltage, comprehensive protection features, plus advanced thermal management circuitry.An advanced integrated TRIAC dimmer detects leading-edge and trailing-edge TRIAC dimmers. This and the load monitoring circuitry allows for bleeder current regulation during each switching cycle. The ICs significantly increase efficiency by disabling the bleeder circuit completely when no dimmer is detected. The combination of a low-side switching topology, cooling via electronically quiet SOURCE pins and frequency jitter ensure extremely low EMI. This reduces the size of the input filter components and greatly reduces audible noise during dimming. 

This design example report presents a 10 W TRIAC dimmable high frequency, power factor corrected buck-boost LED driver employing LYTSwitch�-3 LYT3316D. This LED driver operates in an input voltage ranging from 90 VAC to 132 VAC and delivers an output voltage ranging from 36 V to 40 V at 260 mA. It features single-stage power factor correction, accurate constant LED current regulation, low cost and low component count for compact PCB solution, and integrated protection features.