Mixed signal ASIC for closed loop fluorescent lamp management using novel digital frequency control strategies

The area of nondimming electronic ballasts for fluorescent lamps is dominated by a strong requirement for cost reduction. Mixed signal ASIC technology is already the state of the art in this business. Submicron technologies offer a high logic density on small silicon area and the opportunity to move analogue functionality into the digital section with potentially smaller chip size. This paper introduces a nondimming ballast control IC with a minimum amount of external components and small chip size in an SO8 package. The ballast fully complies with EN standards and supports single lamp and series connected lamps using current mode preheat. The focus in this paper is on the lamp current regulation scheme that is mandatory for this design.