摘要
在光电检测电路中信噪比是衡量电路性能的一个重要参数,因此有必要对前置放大电路进行噪声分析。首先给出了光电二极管和运算放大器的等效电路模型,并分析了光电二极管和运算放大器的噪声来源。然后采用分频段的方法计算前置放大电路的噪声,同时引入等效噪声带宽的概念。最后根据叠加原理和噪声理论,推导出了前置放大器的输出噪声计算方法。结果表明:该方法计算的结果与仿真结果相一致,误差较小。该方法的引入,对于元器件的选择和低噪声电路设计具有很好的参考价值。
Since the signal-to-noise is an important parameter to evaluate the performance of the photo-detection circuit, it is necessary to analyze the noise in pre-amplifier circuit. The equivalent circuit models of the photodiode and amplifier were introduced firstly, as well as the noise sources were analyzed. In addition, the output noise of the pre-amplifier was calculated by dividing closed loop bandwidth and the concept of noise equivalent bandwidth was introduced. At last, a method for calculating the output noise of the pre-amplifier circuit was derived based on superposition principle and noise theory. The results show that the calculated result is consistent with the simulated with low error. This method has a good value of designing low noise circuit and electing the component in engineering.
出处
《半导体技术》
CAS
CSCD
北大核心
2011年第4期304-306,315,共4页
Semiconductor Technology
