Research And Design Of A Boost LED Driver Based On Optimization PSM Mode

SMPS(Switch Mode Power Supply) is used as an efficient and energy-savingpower. It has become the main product of the stabilized voltage supply serving as anessential component of electronic system. LED(Light Emitting Diode) has highlight-emitting efficiency, almost be pollution-free and tens of times or more than usuallight source, which exerting a growing important effect, especially in the past few years.Consequently, the design and study for stable performance, low-cost, and highefficiency LED driver are of great theoretical value and broad market space.Firstly, this paper introduced the status and future trends of Switch mode powersupply and its application on LED and gave a detailed analysis of the switching powersupply design in several key technologies in theory. Then taking the research projects"Design and research of power management integrated circuit theory" in CAD instituteof Xidian University as knowledge background, a high efficient, low EMI(ElectroMagnetic Interference) and Boost LED constant-current driver is proposed. This chipuses extreme state current mechanism to implement the optimization PSM(Pulse SkipModulation) technique, which significantly reduces system power consumption andincrease system response speed. Inside the chip a multi-frequency frequency-jittercircuit is incorporated to reduce EMI of the system. The integrated test/protectioncircuit is used to make the system more stable. The reference voltage circuit, undervoltage lockout circuit, frequency jitter and oscillator circuits, state machines, andcurrent limit comparator is mainly introduced, and the overall simulation results isshowed in the final section.The design and simulation of XD0726are completed using Cadence and Hspicesoftware based on the1μm BCD process. The simulation results show that theperformance is excellent and can satisfy the prospective demand.