Sliding Mode Pulsed Current Averaging IC Drivers for High-Brightness Light Emitting Diodes

Wednesday, March 17 2010

Fewer external components and high power efficiency

This project developed new Light Emitting Diode (LED) driver ICs associated with specific (uniquely operated) switching power supplies that optimize performance for High Brightness LEDs (HB-LEDs). The drivers utilize a digital control core with a newly developed nonlinear, hysteretic/sliding mode controller with mixed-signal processing. The drivers are flexible enough to allow both traditional microprocessor interface as well as other options such as “on the fly” adjustment of color and brightness.

Some other unique features of the newly developed drivers include:

• AC Power Factor Correction;
• High power efficiency;
• Substantially fewer external components should be required, leading to substantial reduction of Bill of Materials (BOM).

Thus, the LED drivers developed in this research optimize LED performance by increasing power efficiency and power factor. Perhaps more remarkably, the LED drivers provide this improved performance at substantially reduced costs compared to the present LED power electronic driver circuits. Since one of the barriers to market penetration for HB-LEDs (in particular “white” light LEDs) is cost/lumen, this research makes important contributions in helping the advancement of SSL consumer acceptance and usage.