In the noise simulation of the multi-stage amplification and filtering circuit shown in the figure, the error log points out:“Direct Newton iteration failed to find .op point. (Use ".option noopiter" to skip.)”. When I simulated the filter circuit and the two-stage amplifier circuit separately, they were successful, but when I connected them in series, the simulation failed. So how can I modify the circuit to solve this problem?
在对如图所示的多级放大滤波电路进行噪声仿真时,错误日志提示:“直接牛顿迭代无法找到.op 点。(使用“.option noopiter”跳过。)”。我分别对滤波电路和两级放大电路进行仿真时,都成功了,但将它们串联起来后,仿真就失败了。那么如何修改电路来解决这个问题呢?