互阻放大器带宽计算方法

摘要

互阻放大器是在光电检测前置放大中常用的一种电路结构.在互阻放大器的设计中没有增益带宽积的概念,其带宽分析往往让设计者感到困惑.为了深入研究互阻放大器的增益带宽特性,在此类比增益带宽积的引出,用单极点近似的方法推导出了互阻放大器增益和带宽的关系,并运用Multisim软件进行了仿真,验证了结论的正确性.指出在互阻放大器中增益和带宽仍然是矛盾的,为互阻放大器的带宽设计提供明确的指导.%The transresistance amplifier is often used in photoelectric detection preamplification. For the transresistance amplifier, people are often puzzled about the bandwidth analysis, because there is no conception of Gain Bandwidth Product in the design of transresistance amplifier. In order to research the gain and bandwidth characteristics of the transresistance amplifier , the relationship between gain and bandwidth of the transresistance amplifier is deduced with the single pole approximation method. The simulation was conducted with Multisim software. The result shows that the conclusion is correct. It makes the bandwidth of transresistance amplifier more predictable.