Abstract: | 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%. |