CMOS低噪声高增益放大器的设计及仿真分析.doc

第*章 具体章节标题 本科学生毕业论文 论文题目： CMOS低噪声高增益放大器的设计及仿真分析 学 院： 电子工程学院 年 级： 专 业： 集成电路设计与集成系统 姓 名： 学 号： 指导教师： PAGE PAGE I 摘要 运算放大器已经成为模拟电路设计中用途最广、最重要的部分。运算放大器简称运放被广泛应用于无线电接收机的高频或中频前置放大级和一些高灵敏度电子设备中。运放在电路中会产生噪声，在一些需要放大微弱信号的情况下，运放自身的噪声对有用信号的干扰可能会很严重，所以设计了一款低噪声系数、高功率增益、工作稳定性强、有足够带宽和较大动态范围的运算放大器电路。 MOS场效应晶体管会在电路中产生噪声，而且随着MOSFET尺寸的减小与信号幅度的降低，电路中低频噪声特性变得越来越重要。论文首先分析运放电路中主要产生噪声的原因，然后结合基本噪声理论对电路中相应的元器件参数进行分析设计，然后针对电路的各项指标要求再对电路的元器件的参数进行调整。运放输入级采用PMOS差分输入的结构，可以提高增益，也起到了抑制噪声的目的，输出级也采用共源共栅形式，可进一步抑制噪声。通过对电路整体的噪声性能分析，优化了电路的噪声特性。最后电路达到了设计的目标：增益带宽积大于60MHz、输入噪声功率谱密度在10MHz时小于35nV/rtHz、DC增益大于60dB、相位裕度大于45o。 关键词 CMOS；运算放大器；低噪声；高增益；带宽 Abstract Operational amplifier (Op amp) is the most important and comprehensive element in CMOS analog integrated circuits. Operational amplifier is widely used in various types of high-frequency or intermediate frequency as a radio receiver pre-amplifier stage or the high sensitivity of electronic devices. MOS field effect transistor (MOSFET) circuit would bring noise under weak signal amplification. Noise interference may be very serious for useful signal in an op amp. Thus, it is very necessary that designing an op amp circuit with low noise, high gain, good stability, sufficient bandwidth and large dynamic range. MOS field effect transistor circuit would bring noise. With the MOSFET sizes decreasing and the signal amplitude decreasing, the low-frequency noise characteristics of the circuit are becoming increasingly important. This paper analyzes mainly noise sources of thee op amp circuit firstly, then designs the corresponding component parameters of the circuit considering of the basic noise theory, and adjusts the parameters of certain components. The input stage of Op amp used PMOS differential input gain enhances direct telescopic structure to improve gain and suppress noise. The output stage is horizontal+output+stage to further suppress noise. Seen from the whole circuit noise performance, the noise characteristics are optimize