Research And Design Of A Multi-frequency And High-efficiency Electronic Ballast Control IC XD3502

Taking the project"Theoretical Research on the Key Technique and the Design for Deep-submicron Power Management IC"as the background, this paper has described the design of a multi-frequency and high-efficiency electronic ballast control IC XD3502, based on the light-emitting mechanism and characteristics of fluorescent and the composition and basic principles of electronic ballasts.XD3502 contains a multi-frequency oscillator, dead time control circuit, adaptive zero voltage switching(ZVS) circuit and so on, by modulating the external capacitors and resistors, the oscillator frequency can be accurately controlled. The chip has four operation modes: preheat mode, ignition mode, adaptive ZVS mode and shutdown mode. The modes are automatically selected by the voltage of the external capacitor, and the capacitance acts as a timer to determine the preheating and ignition time. After the preheat and the ignition mode, the role of the capacitance is changed to stabilize the adaptive ZVS control circuit, in this mode,the dead time of the chip is selected by the voltage of the capacitance. If ZVS is satisfied, the chip slightly increases the voltage to reduce the dead time and to find optimal dead time, which increases the efficiency and decreases the thermal dissipation and EMI of the inverter switches.When the voltage of the external capacitor is decreased below a certain value ,the chip enters into shutdown mode. In addition, the chip also integrates over-temperature protection, undervoltage lockout and so on.After completing the operational principle and designing of the circuits, based on the 0.5μm BCD process from a company abroad using Cadence and Hspice software, the function performance and key characteristics of the IC and its sub-blocks, are simulated. The simulation results verify the correctness of theory and the feasibility of the design method, and perfectly meets the prospective specifications.