关于交流小信号分析

应该海鱼噪声分析等等有关系吧，求更详细更专业的解释

也就是说，对一个电路，比如说运放的频率特性分析，并非是要得到它有多少增益大小用于放大小信号的，是吗?

从波特图中 可以得到增益这一指标，但是这只是频率分析能够得到的一个信息而已

small signal analysis is used to get Bode plot, you can get the loop stability information and BW (speed) of the loop. Time domain simulation is also important.

谢谢回复，我其实想问的是，所谓的小信号放大倍数分析，并非真的用来放大一个信号以给后面的电路处理信号，是吗?

我个人认为小信号分析可以得到很多指标情况，但是放大器最终还是处理小信号的，它的输出必将应用到后级电路。小信号分析只是为了设计该放大器采取的手段。

这都神马和神码阿，，，

OP operates at big signal at its output, you will always connect the OP as close loop (with beta). Small signal analysis will tell you the open loop GBW (open loop Wu ( A(s)x Beta`s ) 0dB frequency in Bode plot ) = close loop -3dB frequency (= 1/time constant) ) & stability information about the close loop circuit. Time domain verification is also important such as step response. OP is usually work at big signal (in designed swing), but not small signal. Small signal analysis is a very good analytical method.But it can not tell you about the SR.

those information are very valuable. thank you ！

AC sims can get bode plot for closed loop AMP application, but NOT limited to those. AC analysis also apply to open loop amp scenario, for example, peaking amp in serdes front end design where the amps are used as open loop...

Sorry, I donot focus on serdes.Analog world is very huge. I just figure out the general condition. Circuit topology is depend on usage condition.