New driver ICs support widest range of TRIAC dimmers

Power Integrations has introduced the LYTSwitch-3 family of LED driver ICs. Ideal for bulbs, tubes and downlights up to 20W, LYTSwitch-3 ICs offer excellent dimming performance with both leading-edge and trailing-edge TRIAC dimmers, and support both isolated and non-isolated topologies.

LYTSwitch-3 ICs feature programmable dimming profiles, enabling designers to optimize drivers for dimming range and efficiency. Deep dimming response is also programmable – to extend dimming range or engage the load-shutdown mode to eliminate the possibility of shimmer. When no dimmer is connected or the dimmer is set at full conduction angle, the IC’s dimmer management circuitry is turned off, improving efficiency. Uniquely, the new driver continuously manages power factor, even in dimming mode, which minimizes apparent power draw (VA) as the bulb dims, preventing power quality excursions in large installations.

LYTSwitch-3 ICs also include a thermal-fold-back feature that automatically dims the light output to compensate for inadequate fixture cooling or high ambient temperatures, preventing damage and increasing lamp lifetime.

Commenting, Hubertus Notohamiprodjo, product marketing director, Power Integrations, said: “These new driver ICs can be used to provide buck, boost, buck-boost, tapped-buck, tapped-buck-boost and isolated flyback topologies. They are compatible with the widest range of dimmers and provide a choice of MOSFET breakdown voltages for optimized designs. This means that multiple single-sided, ultra-small designs can be based around one IC, reducing design cycle time and part inventory.”

Featuring a power factor of greater than 0.9 and THD of less than 10%, LYTSwitch-3 driver ICs meet all international efficiency standards including EN61000-3-2, CEC Title 20, CEC Title 24 and ENERGY STAR. The ICs also provide 3% constant-current (CC) accuracy over load, line and from device to device. Like all Power Integrations products, the highly integrated devices include comprehensive protection features while requiring fewer external components than competing discrete designs, enhancing reliability while reducing BOM costs and PCB footprint, says the company.