90W LED driver controllers support flicker-free operation

March 02, 2016 // By PAUL BUCKLEY
Dialog Semiconductor plc has introduced two LED driver controllers
Dialog Semiconductor plc has introduced two driver controllers for high power commercial LED lighting applications up to 90 W. In these applications flicker-free operation is essential to avoid eye stress where there is long-term exposure to the light source.

Dialog's patented Flickerless technology claims to virtually eliminate flicker through digital control that achieves near-zero line frequency ripple.

The iW3629 (non-dimmable) and iW3631 (dimmable) digital power controllers simplify the design of LED power supplies by replacing up to 45 discrete components. Both devices can be used with small input and output bulk capacitors, and small transformers which cuts power supply size, bill of materials and costs while optimizing performance. The controllers feature better than 0.95 power factor (PF), less than 15% total harmonic distortion (THD) and 85%+ efficiency over a wide load range, easily meeting the requirements of the Design Lights Consortium (DLC).

The controllers comprise a two-stage design with a rectified AC-input (90 to 277 VAC), active start-up, and a boost circuit feeding a flyback converter. The latter provides a constant current drive to the LEDs. Quasi-resonant control in both stages maximizes power efficiency. Dialog's PrimAccurate primary side sensing technology produces tight line and load regulation while eliminating the need for secondary side feedback components. Fast, smooth start-up takes less than half a second and PF settling time is minimal.

The iW3631 dimmable controller has a flicker- and shimmer-free dimming range of 1% to 100%. The device has a built-in interface to industry-standard, 0-10 V analog dimmers, so there's no need for an external driving source or microcontroller, and a dimming interface to support wireless solid state lighting applications.

The iW3629 and iW3631 are sampling now and will be available in production quantities in Q2, 2016.