Deep-dimmable lighting controller IC

October 30, 2012 // By Christoph Hammerschmidt
NXP Semiconductors announced highly efficient GreenChip controller IC for compact, deep-dimmable LED retrofit lamps from 4 to 25 W. The SSL2129A offers best-in-class dimming performance measured in compatibility per watt, for a single-stage mainstream LED driver application. Its straightforward approach also allows the application to remain compact (GU10/PAR16) and highly cost-effective, with a high power factor of more than 0.9. The SSL2129A is designed for use with an external MOSFET and can be configured in both buck (non-isolated) and flyback (isolated) topologies, for 100-120V and 230V mains supply voltages.

With over 600 dimmer types sold worldwide today, nearly all of which were originally designed for incandescent lamps, designing dimmable LED lamps that perform reliably and consistently with a broad variety of dimmers remains a significant challenge for lighting manufacturers. At the same time, as LED efficacy (in terms of lumens/watt) increases steadily, the input power required for retrofit LED lamps is decreasing, raising additional challenges: Today, commercially available LED lamps need about 7 watts to replace a 40-watt incandescent bulb, and 8.7 watts to replace a 60-watt incandescent, but it is precisely under 10 watts that dimmer compatibility becomes particularly difficult.

To address this, NXP has developed a “compatibility per watt” scoring method that takes into account the absorbed mains input power, as well as a metric for compatibility determined by both stability (the ability to avoid visual disturbances such as flicker, shimmer and flashing), as well as controllability (the level to which the user can control and reduce the lamp light output, including dimming range, control span and steps in light level). Based on this parameter, the SSL2129A has demonstrated outstanding dimmer compatibility

Key Features of the SSL2129A include

- Compact, single-stage LED driver solution reducing eBOM cost

- Benchmark dimmer compatibility per watt

- Controller-only SSL driver IC for both non-isolated and isolated topologies

- Designed for retrofit lamps from 4 to 25 W

- High efficiency and high power factor (PF >0.9)

- Easy to use and easy to manufacture.

The SSL2129A deep-dimmable controller IC for LED lighting is now in volume production with product samples available immediately.

For more information visit