US Patent 7420338 Ballast control IC with minimal internal and external components

A ballast controller integrated circuit which executes a specific set of instructions via an integrated state diagram architecture to control a fluorescent lamp or high intensity discharge lamp and protect the ballast. The state diagram architecture controls powering up and down of the IC and the half-bridge circuit driven by the IC, preheating and striking of the lamp, running of the lamp, sensing for numerous possible fault conditions, and recovering from these fault conditions based on the normal maintenance of a lamp, while requiring fewer internal and external components than previous electronic ballasts.