高温6H-SiC CMOS运算放大器的设计  

Design of 6H-SiC CMOS OPAMP operating in high temperature

作　　者：刘莉[1] 杨银堂[1] 

机构地区：[1]西安电子科技大学宽带隙半导体材料与器件教育部重点实验室,陕西西安710071

出　　处：《西北大学学报（自然科学版）》2010年第2期219-223,共5页Journal of Northwest University（Natural Science Edition）

基　　金：教育部重点科技基金资助项目(02074);国家部委预研基金资助项目(41308060105)

摘　　要：目的设计可工作在高温下的6H-SiC CMOS运算放大器。方法该电路基于标准的PMOS输入两级运放而成,考虑泄漏电流匹配添加Dcomp二极管。利用零温度系数理论和泄漏电流匹配的原则对电路管子的尺寸进行确定。通过求解SiMOS管和6H-SiC MOS管零温度系数点来稳定偏置电路。结果利用Hspice进行仿真,当温度从300K变化到600K时,SiC运放的增益和相位裕度的变化率分别为2.5%和3.3%,而Si电路的增益从300K的64dB降到600K的-80dB。由于SiC MOS器件沟道迁移率低导致器件的跨导低于相同尺寸下的Si器件,所以其开环增益也小于相同结构和尺寸的Si OPAMP。结论此电路可以在高温下稳定工作,但是单管的性能较Si单管差。Aim To design temperature stability of 6H-SiC CMOS OPAMP.Methods Taking leakage current matching into account,Diode（Dcomp） is added to node A.According to ZTC and leakage current matching,transistor size is determinated.Biasing circuit is stabilized by ZTC of SiC and Si MOST.Results Circuit operating in 5V is simulated with Hspice.Varation of DC gain and P.M of SiC CMOS OPAMP is 2.5% and 3.3%,respectively.Howerver,gain of Si OPAMP drops from 64dB to-80dB,losing its temperature stability.Advantage of SiC material works under high temperature obviously.SiC devices suffer from some imperfect material properties,such as low channel mobility which will result the low transconductance from the circuit design point of view.Conclusion Circuit designed can be operated in high temperature,but single transistor of SiC is not better than counterpart of Si.

关 键 词：6H-SIC CMOS OPAMP 零温度系数 泄漏电流匹配 温度稳定性 

分 类 号：TN4[电子电信—微电子学与固体电子学]