基于低反馈电阻技术的LED照明驱动芯片设计

Design of power LED lighting driving integrated circuit based on low feedback resistor technique

在开关电源中,输出电压反馈电阻的大小正比于其消耗功耗.为提高芯片系统效率,提出了低反馈电阻技术,低反馈电阻技术关键在于产生低的参考电压与反馈采样电压进行误差放大.给出了低至18 mV的基准电压电路的设计过程和仿真结果,设计了一种基于双极型、互补型、双扩散金属氧化物半导体(BCD)1.6μm工艺的功率LED照明驱动芯片以验证低反馈电阻技术.系统仿真结果表明:电路的运行效率高达95.6%,输出电流纹波系数为(2.14%)/V.

The power consumption of feedback network was proportional to the feedback resistance under constant current for switch power chips. To increase system efficiency, low feedback resistor technique was put forward in this paper. The bottleneck of low feedback resistor technique was to generate an ultra-low reference voltage to amplify the error with feedback sample voltage. A voltage reference as low as 18 mV was designed. A chip based on bipolar, complementary metal-oxide-semiconductor, double-diffused-mos （BCD） 1.6μm process was designed for the power LED lighting driving system to verify the low feedback resistor technique. The simulation result showed that the system efficiency reached 95.6% and the ripples were （2.14 %）/V.