LED driver integrates boost and flyback converters

August 26, 2013 // By Graham Prophet
The iW3623 from Dialog Semiconductor is a SSL LED driver that integrates boost and flyback converters into a single IC, resulting in lower cost and a simplified design.

The iW3623 offers a universal 100 VAC to 277 VAC input range and output power up to 45W. It integrates a boost controller for power factor correction (PFC) and a flyback converter for LED current regulation, while enabling high PF of over 0.95 and low total harmonic distortion (THD) of under 10%. Dialog’s Flickerless design claims near-zero 100 to 120Hz output ripple and the built-in over-temperature protection (OTP) enables lighting designers to deliver a predictable, reliable bulb operating life.

The iW3623 eliminates the need for a secondary-side regulator and optical feedback isolator and allows FETs to be replaced with lower cost bipolar junction transistors (BJTs). It uses quasi-resonant mode switching for both the boost and flyback stages and dynamic base current to optimise conversion efficiency and minimise EMI. It features output power of 3W to 45W and elimination of LED flicker with under 5% 100Hz – 120Hz output current ripple; it includes NTC-based LED over-temperature protection (OTP) and derating, and meets global standards, including the European Union IEC61000-3-2(1) requirement. It is compatible with the Zhaga hot-plug LED module for LED light interchangeability, comes in a 14-lead SOIC package and is priced at $0.93 (1000).

Dialog Semiconductor; http://iwatt.com/