Power Integrations has published a reference design for a 25W LED T8 tube ballast power supply. The design DER-287 meets commercial requirements for power factor more than 0.9 and harmonic distortion EN61000-3-2 Class C. The design is a single-stage converter built around LNK409EG, a member of the LinkSwitch-PH family of LED driver ICs. According to the company, the single-stage technology increases product lifetime by eliminating the opto-isolators and large aluminum electrolytic input bulk capacitors required by conventional two-stage solutions.
In addition to the monolithic design that combines controller, driver, and switching MOSFETs into a single package, the company's LinkSwitch-PH family has protection features including over-temperature and over-current protection, claims the company.
