TRIAC Dimmable LED Driver 14 W circuit diagram

Download source: LNK403-409/413-419 LinkSwitch-PH LED Driver IC Family Single-Stage PFC, Primary-Side Constant Current Control and TRIAC Dimming/Non-Dimming Options

14 W TRIAC Dimmable High Power Factor LED Driver circuit diagram Design Example The circuit schematic in Figure 7 shows a TRIAC dimmable high power-factor LED driver based on LNK406EG from the LinkSwitch-PH family of devices. It was optimized to drive an LED string at a voltage of 28 V with a constant current of 0.5 A (±5%) ideal for PAR lamp retro-fit applications. The design operates over a universal input voltage range of 90 VAC to 265 VAC but provides the specified output current tolerance over a line voltage range of 90 VAC to 132 VAC (this is configurable for high-line only applications by simple component value changes).

The key goals of this design were compatibility with standard leading edge TRIAC AC dimmers, very wide dimming range (1000:1, 500 mA:0.5 mA), high efficiency (>85%) and high power factor (>0.9). The design is fully protected from faults such as no-load, overload and output short-circuit conditions and over temperature.