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.
出处
《半导体光电》
CAS
北大核心
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)
关键词
LED驱动器
振荡器
频率扩展
抑制电磁干扰
低温漂
LED driver power supply
oscillator
frequency extension
EMI suppression
low temperature drift
