集成运算放大器的噪声模型和精确测量

Operational Amplifier Noise Model and Its Accurate Measurement

本文针对目前使用的集成运算放大器噪声模型及其测量方法的缺点，提出比其更加完善适用的噪声模型。根据叠加原理和等效噪声电路理论，推导出求解反相输入端与同相输入端噪声模型的等效噪声功率谱公式，并给出该模型的测量方法。利用自行设计的自动高精度低频噪声功率谱测量系统，对低噪声集成运算放大器ＯＰ－３７进行测试，并给出包括谱相关系数在内的噪声模型参数测量结果。本文为集成运算放大器的噪声模型表达及其测量提供了一个更准确的方法。

In accordance with general operational amplifier (OP AM) noise model which is widely used and its measurement method, a more perfect and applicable noise model was proposed, which has considered the correlation between equivalent input noise voltage source en and noise current source in. And based on superposition theorem and equivalent noise electronic circuit theory, the formulae of the equivalent input noise power spectrum of an OP AM noise model are derived for both inverse input terminal and non-inverse input terminal, and the measurement method of the noise model is given. The measurement for OP-37 is carried out by means of the automatic low-frequency noise power spectrum measurement system, and the measured results of noise model parameters including the spectral correlative coefficient are given. A more accurate method for OP AM noise model expression and its parameter measurement is provided.