求助关于仿真步长的设置，是否感谢！

红红的西瓜

各位大佬，目前希望电路时钟的节点在翻转时候减小步长提高精度，在不翻转的时候增大步长。看了论坛，有如图一的算法，我试了一下，ΔV基本取决于第一项，所以值能改reltol值，但是改了reltol值会使得所有时间步长都减小，有仿真慢的问题。

所以请问各位，瞬态仿真如何设置才能限制节点电压最小跳变值？

david_reg

或许可以试试减小这个tran的option.

transres=1e-9*stop s
                          Transition resolution. The transient analysis attempts to stop at corners of input waveforms (for example, corners of rising/falling edge of a pulse). If such
                          events occur within a time less than transres, the analysis combines the events into one and forces only one time point. The rest of the steps are determined by
                          error control. This may lead to loss of detail.

Spectre has a built-in minimum transition time set to 1e-9*(stop-start) s. Any transitions that happen faster than this will be ignored or combined with other events resulting in a loss of detail. The workaround is to shorten the stop time. If you cannot modify the simulation time, a transient option called "tranres" will permit you to specify a larger or smaller minimum transition time.  



Here is a usage example:



tran tran stop=1m annotate=status maxiters=5 transres=1e-10

红红的西瓜

david_reg 发表于 2023-12-6 02:17
或许可以试试减小这个tran的option.

transres=1e-9*stop s

感谢回复！我试试看