The article presents the buck converter for the application on headlights of vehicle with chip-level design. The LED components are used as for lighting source, which near/far lights are controlled with high-current switching circuit in the chip. The level-shift circuit and its current driver is proposed to control the input of high-voltage power MOS. The bypass method is presented to reduce the transient time as load current changes suddenly. The input voltage widely ranges from 8 to 21 V while keeping a stable output voltage with 6 V. The chip current can output from 20 to 1500 mA with excellent regulation. This chip had been implemented with TSMC0.25 µm HV- process, and the size of the circuit layout is about 8.6 mm2, where includes power switch and far/near lighting switches. Measurements show that peak efficiency can achieve 86.3%. The power regulation is excellent, where the load regulation is only 0.3%, and the line regulation is only 0.5%.
蜂窝网中的协作定位技术作为一种高性能的定位技术,改善了非视距传输(Non Line of Sight)和多径效应对移动终端(Mobile Station)定位的影响,扩展了定位服务范围。文中综述了协作定位技术原理与蜂窝网中协作定位技术的研究现状和应用,对现阶段的协作定位技术进行了分析比较,并展望了其发展方向。 相似文献