新型的低电压高精度电流镜设计  

New High-precision Current Mirror for Low Voltage Application

作　　者：谭晓昀[1] 孙明[1] 王嘉琪[1] 刘晓为[1,2] 

机构地区：[1]哈尔滨工业大学MEMS中心,哈尔滨150001 [2]微系统与微结构制造教育部重点实验室,哈尔滨150001

出　　处：《微处理机》2010年第5期1-4,共4页Microprocessors

摘　　要：电流镜是模拟电路当中的基本单元,其性能对整体电路的性能起着关键作用。基本电流镜不能理想复制参考源的电流,其输出电流随外界输入电压的变化而变化,且基本电流镜对输入电压存在着最小值的要求。传统的cascode电流镜虽然能够较精确的复制参考源电流,但是仍然存在着对输入电压最小值的要求,该值大约为2Von。为了对基本电流镜的两个缺陷进行改进,提出了一种新型的低电压高精度电流镜结构,该电流镜能够理想的复制参考源电流,其输出电流对外界输入电压不敏感。通过仿真得出,op1和op2的低频增益为83dB,带宽为7.9MHz,最小输入电压大约可以减小到大约25mV,其输出电流对电压的斜率slope=0。Current mirror is one of the basic units in the analog IC design and encapsulate many of the key issues in lots of ASIC.Basic current mirror cannot copy the reference current ideally,and the output current changes with the input voltage outside.And moreover,the input voltage has minimum limitation.Although traditional cascode current mirror can copy the reference current accurately in some way,it also has the minimum limitation for the input voltage.In order to improve the two defects above,a new high-precision current mirror for low voltage application was designed.The current mirror can copy the reference current precisely and will not change with the input voltage.Through simulation,the voltage gain of amplifier op1 and op2 is 83dB,and the bandwidth is 7.9MHz.The minimum input voltage is about 25mV,and the slope between the output current and input voltage is 0.

关 键 词：低电压 电流镜 放大器 

分 类 号：TN492[电子电信—微电子学与固体电子学]