文档介绍：西安电子科技大学
硕士学位论文
用于光电检测的集成低噪声放大器设计
姓名:周海宁
申请学位级别:硕士
专业:微电子学与固体电子学
指导教师:庄奕琪
20100101
摘要 I
摘要
随着探测技术的发展,在科学研究和工业应用中,需要对越来越多的微弱信
号进行放大处理。然而电路中的噪声成为微弱信号放大的主要制约因素,它通常
会限制电路中输出信号的精度。本文在对噪声理论及 CMOS 电路中主要噪声分析
介绍的基础上,深入研究了降低电路中低频噪声的技术,包括自动调零、相关双
采样和斩波稳定等。通过分析和对比这些低噪声技术,结合放大电路的实际应用
环境和指标要求,本文设计了一款用于光电检测的集成低噪声微弱信号放大电器,
该放大电路内部采用了斩波稳定结构来降低噪声和失调,通过调制解调的方法将
信号调制到没有 1/f 噪声的高频处,再经过放大器放大后解调回原始基带,在此过
程中电路产生的噪声和失调只经过一次调制,被调制到了高频处,可利用低通滤
波器滤除,从而达到降低噪声的目的。整个放大电路主要包括前置放大器、高通
滤波器、解调器和开关电容低通滤波器四个模块。在输入调制中采用光信号调制
的设计,大大降低了 MOS 开关调制器中由于开关非理想效应引入的残余失调。芯
片采用混合工艺进行流片,仿真和测试结果表明该电路通过斩
波稳定技术实现了信号的放大同时抑制了噪声。在斩波频率为 50kHz 时,该放大
电路的低频等效输入噪声为 HznV/ 。

关键字: 低噪声微弱信号斩波稳定技术光调制
Abstract II
Abstract
With the development of detection technology, more and more weak signals are
processed in basic research, industrial application and so on. Noise es the main
limitation in amplifier, which could affects the accuracy of usable signal of circuit easily.
On the basis of noise theory and analysis of noise in CMOS circuits, this paper presents
several methods that are used to reduce low-frequency noise and offset of amplifier.
These methods include optimized structure of op-amplifier, autozeroing (AZ) technique,
correlated double sampling (CDS) technique and chopper stabilization (CHS) technique.
After analysis parison, this thesis presents a low noise circuit used for weak
signal amplification in photoelectric detection. The amplification circuit uses the
chopper stabilization technique to reduce the offset and low-frequency noise. It applies
modulation to transpose the signal to a higher frequency where is no 1/f noise, and then
demodulates the signal back to the baseband after amplification. Since the noise and
offset are modulated only once, they are transposed to the Since the noise and offset are
modulated only once, they are transposed to the high-frequency, which can be easily
removed by a low-pass filter, leaving the ampli