一种采用改进自调零技术的误差放大器设计  

An Error Amplifier with Improved Auto-Zeroing Technique

作　　者：王松林[1] 张树春[1] 叶强[2] 王晓光[2] 罗鹏[1] 丁睿[2] 

机构地区：[1]西安电子科技大学机电工程学院,陕西西安710071 [2]西安电子科技大学电路CAD研究所,陕西西安710071

出　　处：《复旦学报（自然科学版）》2010年第6期667-673,共7页Journal of Fudan University：Natural Science

基　　金：国家自然科学基金(60876023)资助项目

摘　　要：设计了一种乒乓结构的误差放大器,采用改进的自动调零技术,实现连续时间内的信号放大和失调消除.利用可变增益电流镜构造了带辅助输入端的运放,克服了传统的失调存储技术对环路稳定性的影响.由于失调周期性的校准,很大程度上减小了开关频率范围内的1/f噪声,还可以消除由温度变化引起的运放失调漂移.采用0.6μm CMOS工艺进行了仿真验证,结果表明,误差放大器低频增益可达91.96 dB,-3 dB带宽为11.58 kHz,静态耗电流仅为14μA,失调消除电路可将1~20 mV的输入失调电压消除至20μV以内.An error amplifier with Ping-Pong structure is presented.An improved auto-zeroing technique is used to amplify signals continuously and cancel offset.The amplifier with an auxiliary input is constructed through a programmable current mirror,which avoids the influence of the traditional offset storing technique on the loop stability.Because of the periodical adjusting of the offset,the 1/f noise in the range of switching frequency is obviously reduced,and the offset drift caused by temperature change is also cancelled.The simulation has been done with 0.6μm CMOS process.The results show that the gain of the error amplifier at low frequency can be up to 91.96dB with-3dB bandwidth 11.58kHz.The quiescent current is only 14μA,while the input offset voltage of 1~20mV can be reduced to less than 20μV.

关 键 词：误差放大器 乒乓结构 失调消除 自动调零 

分 类 号：TN722[电子电信—电路与系统]