摘要
针对多个开关电源并联或串联的系统中产生的差频噪声问题,介绍了一种消除差频噪声的外同步技术,并设计了一种可用于开关电源控制芯片的具有外同步功能的窗口比较式CMOS振荡器。Hspice仿真结果表明,在非外同步模式下,该振荡器工作于固有频率550kHz。在外同步模式下,只要外同步信号的频率满足要求(585kHz～750kHz),振荡器频率将跟随外同步信号,从而最大程度地减小系统中的差频噪声。
Based on the analysis of problems caused by beat frequencies in systems with switch-mode power supplies in series or parallel, an external synchronization technology aimed to the elimination of beat frequencies is proposed. Besides, a window-comparator CMOS oscillator with external synchronization ability, which can be applied in switch- mode power supplies, is designed. HSPICE simulation results show that the operating frequency of the oscillator is internally set at 550kHz and the oscillator can be synchronized with an external clock signal if only the frequency range of this signal is from 585kHz^750kHz.
出处
《微电子学与计算机》
CSCD
北大核心
2007年第12期183-186,共4页
Microelectronics & Computer
关键词
外同步
差频噪声
CMOS
振荡器
external synchronization
beat frequency
CMOS
oscillator
