Date: 18/02/2009

LED driver IC operating directly from mains power with dimming features

NXP Semiconductors has launched SSL2101, the dimmable mains LED driver. With no such device available in market with dimming feature, this LED driver IC also operates directly from rectified mains power saving few of passive components. The SSL2101 is a small form factor Switched Mode Power Supply (SMPS) controller IC which can drive lighting systems with variable power requirements which include LED retro-fit lamps, LED modules, LED spots, down-lights and LED strings for retail displays.

The dimming capabilities offered by the SSL2101 create unique opportunities for lighting system designers to produce more energy efficient systems.

"Meeting the constantly evolving lighting needs and supporting the green lighting revolution, NXP's solutions help to deliver lighting products with improved efficiency," said Robert de Jonge, director of marketing for power & lighting solutions, NXP Semiconductors. "The SSL2101 enables products to have lower energy consumption, longer lifetimes, smaller form factors and increased robustness."


The SSL2101 includes a high-voltage power switch and can start-up directly from the rectified mains voltage, so no external startup circuit is required. To support its dimming capabilities the SSL2101 contains two integrated high voltage-switches for bleeder operation and an input that can be used to sense lamp power usage and activate additional bleeder action when needed.

The SSL2101 also offers non-isolated (buck) and isolated (fly-back) solutions in one chip. It has an additional input that can be used to detect demagnetization of the inductive element, ensuring full utilization of the magnetic material and preventing hard switching of the current. The device has in-built circuitry to reduce capacitive switch-on losses and optimize valley switching efficiencies therefore making the SSL2101 an effective power converter at low power levels. The SSL2101 uses on-time mode control and frequency control to control the LED brightness. This combined effect of both frequency variation and on-time control results in a dimming curve similar to that of an incandescent lamp. The usage of both control methods also enables the designer to reduce peak current, helping in the reduction of audible transformer or inductor noise.

The IC offers a reliable and safe thermal solution via a thermal enhanced package with a built-in Over Temperature Protection (OTP). It also features Short-Winding Protection (SWP), Over Current Protection (OCP) and is aligned with regulations on safety and power factor.

Availability: Now in volumes
Price: Each $1.50