Dimmable LED lighting design simplified across a wide range of dimmers

06-02-2015 | Fairchild | Design Applications

A highly-integrated LED controller solution for low-cost, and highly-reliable LED lighting solutions from 5W to 30W, the FL7734, a new phase-cut dimmable single-stage LED driver has been introduced by Fairchild The FL7734 enables designers to quickly achieve great light quality designs with high dimmer compatibility while integrating full power factor correction (PFC) circuitry to meet power factor (PF) and total harmonic distortion (THD) requirements. The FL7734 solution uses Fairchild’s unique active dimmer driving technology to eliminate visible flicker or shimmer symptoms and deliver over 90% dimmer compatibility with a variety of leading edge, trailing edge and digital dimmers from a wide range of manufacturers. The solution fully meets NEMA SSL 7A-2013 and ENERGY STAR standards and provides a programmable dimming curve and input current management flexibility, says the company. “The FL7734 driver simplifies LED light designs with broad dimmer compatibility,” said James Lee, technical marketing manager, Fairchild. “LED bulb and phase-cut dimmer suppliers are different, so a good phase-cut dimmable bulb has to operate well with many different dimmers. We developed the FL7734 with this in mind.” The FL7734 is a fly-back (or Buck-Boost) pulse-width modulator (PWM) controller that uses an advanced Primary-Side Regulation (PSR) technique, which minimizes the external components required for implementation and therefore lowers BOM. To meet stringent LED brightness control requirements, the FL7734 uses Fairchild’s innovative TRUECURRENT PSR technology for tight constant current (CC) variation with a tolerance of less than ±1% in the wide line voltage range. The FL7734 can be used in a wide variety of lamps including GU10, candle lights, A19 and PAR30/38 bulbs, down and flat lights, and indoor and outdoor lights. Both solutions deliver a highly precise CC control with better than 1% variation over the entire universal line input operating range. To meet safety regulations and ensure long-term reliability, the FL7734 device adds comprehensive protection features including dual overvoltage protection for both open-VS and open-VDD conditions, output diode short, and open/short protection for current sense resistor and every pin of the control IC. It also features open-LED, short-LED and over-temperature shutdown protections. The FL7734 is available in 16-pin Small-Outline Package (SOP).

By Craig Dyball