一种低温漂低功耗RC振荡器的设计  

Design of a low temperature drift low power RC oscillator

作　　者：鲁澳宇 邹敏 喻华 邹望辉 LU Aoyu;ZOU Min;YU Hua;ZOU Wanghui(Changsha University of Science and Technology,Changsha 410114,China;Guangdong Synwit Integrated Circuit Co.,Ltd.,Changsha 410205,China)

机构地区：[1]长沙理工大学,湖南长沙410114 [2]广东华芯微特集成电路有限公司,湖南长沙410205

出　　处：《微电子学与计算机》2024年第12期77-84,共8页Microelectronics & Computer

基　　金：湖南省教育厅重点项目(23A0260)。

摘　　要：为了降低温度对MCU时钟频率的影响以及减小MCU的功耗,基于0.18μm标准CMOS工艺,设计了一种低功耗RC振荡器。该振荡器采用PTAT(Proportional To Absolute Temperature)电流和CTAT(Complementary To Absolute Temperature)电流相加给电容充电,对振荡器的频率进行温度补偿,降低温度对输出振荡频率的影响;采用低功耗亚阈值运算放大器代替传统比较器,极大降低了振荡器的功耗;设计电流修调电路,提高了振荡器输出频率的精度。该振荡器的供电电压为1.8 V,工艺角为TT时,输出振荡频率为231 kHz,静态工作电流为9.6μA;在温度变化为-25~125℃时,频率变化范围在1%以内,温度系数为5.9×10^(-5)℃^(-1),最大工作电流仅为12μA;在电源电压变化0.1 V时,频率变化范围在1.8 kHz以内。In order to reduce the impact of temperature on MCU clock frequency and reduce MCU power consumption,a low power RC oscillator based on 0.18μm standard CMOS technology is designed.The capacitor is charged by adding PTAT(Proportional To Absolute Temperature)current and CTAT(ComplementaryTo Absolute Temperature)current,which temperature compensates the frequency of the oscillator.Reduce the effect of temperature on the output oscillation frequency.The low power subthreshold operational amplifier is used instead of the traditional comparator,which greatly reduces the power consumption of the oscillator.The current adjusting circuit is designed to improve the accuracy of the oscillator output frequency.The power supply voltage of the oscillator is 1.8 V,and when the process angle is TT,the output oscillation frequency is 231 kHz,and the static working current is 9.6μA.When the temperature changes from-25℃to 125℃,the frequency variation range is within 1%,the temperature coefficient is 5.9×10^(-5)℃^(-1),and the maximum working current is only 12μA;When the power supply voltage changes by 0.1 V,the frequency variation range is within 1.8 kHz.

关 键 词：RC振荡器 低功耗 温度补偿 电流修调 

分 类 号：TN752[电子电信—电路与系统]