Power Integrations announced four reference designs describing drivers for dimmable PAR 30 and PAR 38 LED light bulbs. Jointly developed by Power Integrations and CREE, the designs showcase the combination of Power Integrations 19 LYTSwitch!22-4 driver ICs and CREE MT-G2 EasyWhite LEDs. DER-364 and DER-365 detail low- and high-line PAR 30 LED bulb drivers, respectively, while DER-350 and DER-396 address low- and high-line PAR 38 bulbs. These and other reference designs are hosted at www.powerint.com/ledrivers/cree.
LYTSwitch-4 ICs are highly efficient and deliver accurate output current regulation in bulb and tube replacement applications and high-bay lighting. The devices simplify design and reduce cost while ensuring that lamps deliver uniform light output and provide exceptional performance in TRIAC-dimmable applications. LYTSwitch-4 ICs combine PFC and constant current in a single-stage topology, resulting in power factor greater than 0.95 and typical efficiencies of better than 90%. The single-stage approach also eliminates temperature-sensitive electrolytic bulk capacitors, greatly increasing the bulbs 19 reliability and lifetime. LYTSwitch-4 ICs also operate at a high switching frequency (132-kHz), enabling smaller, lower-cost magnetics to be used, while frequency jittering reduces the need for EMI filtering. These factors combine to deliver LED-driver designs that fit easily into space-restricted bulbs.
Designs based on the new drivers easily meet EN61000-3-2C regulations for total harmonic distortion (THD), and can achieve less than 10% THD. Regulation is better than +/- 5% across load and production spread, reducing the need for over-design to meet minimum luminance targets and cutting system cost. LYTSwitch-4 drivers deliver excellent dimming performance down to low conduction angles with leading-edge or trailing-edge TRIAC dimmers. Start-up is very fast 13 typically less than 500 milliseconds even when dimmed to less than 10% light output 13 and pop-on is virtually eliminated.