运放自激问题

不稳定,运放相位裕度不够

～～～～～

偶也遇到过，用四片封装的，负反馈电路，有时在没有输入信号的情况下出现了1M左右的输出，很是奇怪，还在摸索中

不想仔细分析的话，一个快速dirty的办法就是反馈电阻上并个电容。

学习！

这是易络盟技术支持回答我的：
Due to the strong (i.e., unity gain) feedback and certain non-ideal characteristics of real operational amplifiers, this feedback system is prone to have poor stability margins. Consequently, the system may be unstable when connected to sufficiently capacitive loads. In these cases, a lag compensation network (e.g., connecting the load to the voltage follower through a resistor) can be used to restore stability. The manufacturer data sheet for the operational amplifier may provide guidance for the selection of components in external compensation networks. Alternatively, another operational amplifier can be chosen that has more appropriate internal compensation.
我用有道大致翻译了下：
由于强烈的(即统一获得反馈信息和某些不理想的特点,真正的运算放大器反馈系统很容易有稳定性差的利润（这里我不知道怎么翻）。因此,系统可能是不稳定的充分容性负载相连时。在这种情况下,一个滞后补偿网络(例如,连接荷载通过电阻电压追随者)可以用来恢复稳定。制造商说明书关于运算放大器可以指导产品零部件的选择在外部补偿网络。或者,另一个运算放大器,可以选择适当的内部补偿。