摘要
设计了一种结构简单,低温漂,具有频率扩展功能的振荡器.该电路利用温度补偿电路输出无温度系数的电流,通过TRIMMING电路精确调节电流的大小,在逻辑控制下对电容充放电,经过双门限比较器和整形电路产生稳定的200kHz的方波信号.同时,分频电路产生逻辑信号控制振荡器的扩展电容大小,使振荡器具备频率扩展功能,可以有效地降低电磁干扰,增强系统的电磁兼容能力.本电路采用0.5μm BICMOS工艺,利用Hspice和Cadence软件进行仿真,在芯片系统典型应用环境下仿真得到振荡频率为200.8kHz,当温度在-40~125℃之间变化时,振荡器的频率随温度的偏移在±1%以内.频率扩展范围在中心频率附近浮动±5%左右,该振荡器已经成功应用于一款AC/DC电源管理芯片的设计之中.
A simple structure frequency extension and low temperature drift oscillator is presented.By temperature compensation and trimming circuit a low temperature current is used to charge and discharge a capacity.Compared with double-threshold comparator and shaping circuit,200 kHz signal is obtained.Meanwhile,the oscillator with frequency extension by divider circuit generating logic signals to control the expansion capacitor size to reduce the electromagnetic interference and enhance electromagnetic compatibility of the system.The oscillator based on 0.5μm BICMOS technology library,Cadence and Hspice are used to circuit simulation to get the oscillation frequency of200.8kHz under the typical applications.The frequency varies migration range is within ±1% and ±5% floating with temperature changing in-40~125℃.The oscillator has been successfully applied to the design of an AC/DC fly-back power management chip.
出处
《微电子学与计算机》
CSCD
北大核心
2015年第3期127-131,共5页
Microelectronics & Computer
基金
国家自然科学基金项目(61271090)
国家高技术研究发展计划("八六三"计划)重大项目(2012AA012305)
关键词
开关电源
振荡器
低温漂
频率扩展
电磁兼容
switching oower supply
oscillator
low temperature drift
frequency extension
EMC
