用于LED驱动器的扩频振荡器的设计与实现  

Design and Implementation of Frequency Extension Oscillator for LED Driver

作　　者：王慧丽[1] 冯全源[1] 

机构地区：[1]西南交通大学信息科学与技术学院,微电子研究所,成都611756

出　　处：《半导体光电》2017年第1期126-130,共5页Semiconductor Optoelectronics

基　　金：国家自然科学基金项目(61531016,61271090);四川省科技支撑计划项目(2016GZ0059,2015GZ0103)

摘　　要：为了解决传统LED驱动器引入的电磁干扰(EMI)问题,提出了一种具有扩频功能的片内振荡器。该电路采用频率扩展技术对时钟进行频率调制,可有效抑制电磁干扰,并具有固定频率模式(FFM)和扩频模式(FEM)两种工作模式,且固定频率时温度漂移小。采用0.18μm BCD进行了工艺仿真,结果表明:扩频模式下,振荡器的中心频率为558kHz,扩频范围为6.09%,频率抖动周期为57.8μs,EMI能量降幅高达12dB,显著降低了电磁干扰,适用于对电磁兼容(EMC)性能要求很高的特定LED驱动器中。An oscillator with the function of frequency extension was proposed to suppress the electromagnetic interference（EMI）problem in LED driver. With the clock frequency modulated by frequency extension technology,EMI can be restrained effectively,and two working modes of frequency-extension mode（FEM）and fixed frequency mode（FFM）can be choosen,which drifts little across temperature.Process simulations based on 0.18μm BCD show that the clock was extended 6.09% up and down the central frequency of 558 kHz in a period of57.8μs,and EMI power reduces by 12 dB.Due to its inhibition of EMI,the circuit was suitable for LED driver power supply that requires higher electromagnetic compatibility.

关 键 词：LED驱动器 振荡器 频率扩展 抑制电磁干扰 低温漂 

分 类 号：TN752[电子电信—电路与系统]