Design Of An Electronic Ballast Driver IC Used For CFL

Energy conservation and environmental protection have become the themes of our era, which deserves all of us to practice. We cannot live without light, electric light source with high efficiency and energy saving plays a key role in energy conservation and emission reduction, among which fluorescent lamp is most widely used.The target of the paper is to design an electronic ballast drive IC used for small power compact fluorescent lamp(CFL), which monolithically integrates high voltage half-bridge power MOSFET and low voltage control circuits. The low voltage for control circuits is generated internally. Sweep and glow time control function provides preheat for the filament and shorten the glow time, which prolong the life of lamp. Oscillation frequency of the build in oscillator can be adjusted by the outside RC. Dead time control circuit can prevent the high side power MOSFET and low side power MOSFET breakover simultaneously. High side driving circuit with pulse-dropdown level shifter can reduce the power dissipation of the chip. The proposed IC is easy to drive CFL with few external components. The main job of this paper includes:â‘  The filament model of CFL is analyzed; The working principles of the sub circuits of the electronic ballast are introduced and their typical circuits are discussed.â‘¡ The block diagram of the proposed IC is given and its working principle is analyzed; The typical application of the chip is provided and the method to calculate its component values is discussed.â‘¢ The working principle of each module is described in detail and the simulation results with cadence are given, the modules are: VDD control module used for generating internal low voltage and bias voltage for other modules; sweep and glow time control module used for preheating the filament and shortening glow time; oscillation module whose frequency can be adjusted by the RC outside; frequency-halving module which transfers the output of oscillator to square wave with half frequency and 50% duty cycle; dead time control module used for preventing the high side power MOSFET and low side power MOSFET conducting at the same time; high side driving module with pulse-generator, high voltage level shifter and square wave inverter. Finally we provide the whole circuit and its simulation result, which meets the design requirements.