摘要
振荡器是许多电子系统的主要部分．相对于晶体振荡器，基于CMOS工艺的环形振荡器具有良好的抗震动及抗电磁干扰性能，在车载系统等震动及电磁干扰条件较为严酷的应用场合表现出优势．本文介绍了一种频率为8MHz的CMOS环形振荡器的设计，工作电压范围是2．7～5．5V，工作温度范围是-40～125℃．该振荡器对CMOS环形振荡器的固有缺点进行了针对性的设计．设计中使用的改进的延时单元以及激光校准电路克服了CMOS环形振荡器输出频率片间偏差较大的缺点；使用内部电压源以及电源电压无关的电流源，克服了其易受电源电压影响的弱点．该CMOS振荡器使用HSPICE软件仿真工具设计，并采用UMC0．6um工艺制作，测试验证结果表明，电源电压从2．7V变化到5．5V，振荡器输出频率最大变化范围为±4％．
Oscillator is an integral part of many electronic systems. Unlike crystal oscillator circuits, the CMOS ring oscillator is highly resistant to vibration and EMI,this feature makes it a good choice in the high vibrancies or EMI occasions such as automobile environments. An 8 MHz CMOS ring oscillator operates under supply voltage range 2.7-5.5 V and temperature range --40-125℃ is presented. Special design considerations are included for the disadvantage in CMOS ring oscillator. The improved delay cell and la- ser trim circuit increase the output frequency accuracy. The internal power supply and the power supply voltage independent current source reduce CMOS ring oscillator＇s reliance on power supply voltage. This oscillate circuit is designed with HSPICE tool, and be fabricated in UMC 0.6 um process. Test results illustrate that output frequency vary ±4% from the nominal frequency 8 MHz in the whole power supply voltage range 2.7-5.5 V.
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2008年第4期519-523,共5页
Journal of Xiamen University：Natural Science
基金
福建省自然科学基金(2002H020)资助
关键词
环形振荡器
电源电压无关的电流源
内部电压源
输出缓冲
激光校准
ring oscillator
power supply voltage independent current source
internal power supply
output buffer
laser trim
