Fairchild introduces tangential dimmable single-stage LED drivers

     Fairchild introduced the FL7734 Tangent Dimmable single-stage LED Driver, a highly integrated LED controller solution for low-cost, high-reliability LED lighting solutions from 5 W to 30 W. The FL7734 helps designers quickly achieve superior lighting quality design and high dimmer compatibility, while integrating power factor correction (PFC) circuits to meet power factor (PF) and harmonic distortion (THD) requirements.

     The FL7734 solution uses Fairchild's unique active dimmer drive technology to eliminate visible flicker or shimmer and is more than 90% compatible with leading edge, trailing edge and digital dimmers from a variety of manufacturers. The solution fully meets NEMA SSL 7A-2013 and Energy STAR ® standards and offers flexible programmable dimming curves and input current management.

     James Lee, technical Marketing Manager at Fairchild, said, "The FL7734 driver is compatible with a wide range of dimmers to simplify LED lighting design. LED bulbs and tangential dimmer suppliers vary, so a good tangential dimmer bulb must be able to work with a variety of different dimmers. We developed FL7734 for this purpose."

     The FL7734 is a flyback (or buck-boost) pulse-width modulator (PWM) controller that uses advanced primary end regulation (PSR) technology to minimize the required external components, thereby reducing the BOM. To meet stringent LED brightness control requirements, the FL7734 uses Fairchild's innovative TRUECURRENT®PSR technology for compact constant current (CC) variations with a content difference of less than ±1% over a wide line voltage range.

     Like the FL7733A introduced by Electronica in November last year, the FL7734 can be used in a wide range of lighting products, including GU10, candlelight, A19 and PAR30/38 bulbs, downlights and flat lights, indoor and outdoor fixtures. Both solutions achieve high-precision CC control and less than 1% variation over the entire operating range of the common line input.

     To meet safety regulations and ensure long-term reliability, the FL7734 adds comprehensive protection features, including dual overvoltage protection for open VS and open VDD conditions, output diode short circuit, and open/short circuit protection for electrical resistance measurement and control of each pin of the IC. The device also has LED open circuit, LED short circuit and overtemperature shutdown protection.