Charge pump power-factor-correction dimming electronic ballast

A voltage-source charge pump power-factor correction (CPPFC) continuous dimming electronic ballast is proposed in this paper. The basic charge pump PFC principle is presented, and its unity power factor condition is then reviewed. Constant lamp power control and crest factor correction technique in dimming mode operation are then discussed. A continuous dimming controller with average lamp current control and duty-cycle modulation is developed so that the lamp is able to operate in constant power and low crest factor from 20% to 100% dimming level. The developed dimming electronic ballast has features of higher than 0.99 power factor, low crest factor, and low-DC-bus voltage.