高速精密运放的模型建立方法研究

Research on Modeling Method of High Speed Precision Operational Amplifier

针对高速精密运算放大器的高频模型不精确问题,提出了一种建立精确的运算放大器开环增益模型的方法。通过分析高低频段的零极点个数和位置推导出精确的高速精密运放的开环增益数学模型。实验结果表明,建立的新模型与原运放的开环增益相比,数据相对误差不超过4%。新模型可以指导运放频率稳定性补偿设计,具有较好的通用性。

For the inaccuracy of the high frequency model for high speed precision operational amplifier, a precise method of build- ing open loop gain for operational amplifier is proposed in the article. By the analysis of high and low frequency pole-zero, the open loop gain mathematical model of high-speed precision operational amplifier is derived. The experimental results show that the error of open loop gain is less than 4% that compared with the new model and the original amplifier. The new model may guide to design the frequency stability compensation of the operational amplifier, and be applied in a wide range.