一款基于电荷泵高压内电源的恒定跨导轨到轨运算放大器  

A rail-to-rail operational amplifier with constant transconductance base on charge pump high voltage internal power supply

作　　者：张俊安 李新星 杨法明 林涛 徐金贵 李铁虎 ZHANG Jun’an;LI Xinxing;YANG Faming;LIN Tao;XU Jingui;LI Tiehu(School of Artificial intelligence,Chongqing University of Technology,Chongqing 401135,China;Chongqing Semi-chip Electronics CO.,LTD,Chongqing 401135,China)

机构地区：[1]重庆理工大学两江人工智能学院,重庆401135 [2]重庆中科渝芯电子有限公司,重庆401135

出　　处：《微电子学与计算机》2023年第4期101-110,共10页Microelectronics & Computer

基　　金：国家自然科学基金资助项目(62004020);重庆市科技局科技项目(cstc2018jszx-cyztzxX0050,cstc2020jcyjmsxmX0347)资助;重庆市教委科学技术研究项目(KJQN201801119,KJQN201901108,KJQN20210110,KJQN202101103,KJQN202101137)资助;重庆理工大学科研启动基金资助项目(2017ZD24,2017ZD58,2019ZD06,2019ZD113).

摘　　要：设计了一款基于电荷泵高压内电源的恒定跨导轨到轨运算放大器.输入级采用PMOS差分对结构,通过电荷泵产生高于电源电压的输入级内电源,使运放在轨到轨输入范围能正常工作并保持输入跨导恒定.电荷泵电路所需的时钟信号通过内部振荡器电路产生,再通过电压自举电路和时序电路产生所需电平的非交叠开关控制信号,最后利用时间交织结构输出连续稳定的高压内电源.在电荷泵实现中还采用了辅助开关结合跟随运放的结构降低了主开关在切换时的毛刺.该运放在折叠式共源共栅结构中使用增益自举结构提高了总体增益,输出级采用class AB类输出结构实现轨到轨输出.该运算放大器基于0.5μm CMOS工艺完成电路与版图设计,仿真结果表明,在5 V电源电压下,直流增益为150.76 dB,单位增益带宽为53.407 MHz,相位裕度为96.1°,输入级跨导在轨到轨输入共模范围内的变化率为0.00125%.A constant span rail-to-rail operational amplifier based on charge pump high voltage internal power supply is designed.The input stage adopts a simple PMOS differential pair of the input stage,and the power supply of the input stage is increased through the charge pump,so that the transport is placed to realize the rail-to-rail input while keeping the transconductance constant within the working range.The external clock input of the charge pump used in this paper is the output clock of the comparator,which generates the non-overlapping signal required by the charge pump switch through the time interleaving circuit and the voltage bootstrap circuit,and charges and discharges the capacitor through the conversion of the switching signal,and finally,output the high-voltage internal power supply alternately.The structure of auxiliary switch with following operational amplifier is adopted in charge pump implementation to reduce the burr of main switch during switching.The amplifier also uses the gain bootstrap structure in the foldable common source common gate structure to improve the overall gain,and the output stage adopts the Class AB output structure to achieve rail-to-rail output.Simulation results show that the open-loop gain of the operational amplifier is 150.76 dB,the unity-gain bandwidth is 53.407 MHz,and the phase margin is 96.1°under the 5V power supply voltage.The rate of change of the input stage transconductance within the rail-to-rail input is 0.00125%.

关 键 词：恒跨导 轨到轨 高压电荷泵 运算放大器 

分 类 号：TN722[电子电信—电路与系统]