cadence仿真振荡器，如何能加速起振？

yangqinghui

请教一下大家！

后仿起振太慢了要振3天，但如果用于动态totem的后仿，我不关心起振过程，只关心最终的稳定下来的那一段，有没有一种方法，能够模糊起振过程从而加速起振呢？

esbwong

transient options form -> misc tab. -> additionalParams
linearic=yes oscfreq=<actual_oscillator_freq>

https://community.cadence.com/ca ... crystal-oscillators

aznsj

SET initial voltage to the VCO internal nodes.  .ic .... you can also lower your simulator accuracy setting for the start up .

eelin

给个transient noise

david_reg

也可以试试用一个开关先把振荡器环路里面的某个低电容节点（比如某些逻辑门的输入）拉到某个固定点位（比如地），这时由于电路中没有高频振动节点，电源上电和其他偏置电路的电压建立到稳定就会快很多，等这些节点都充分建立后再断开开关，振荡器通常会很快进入最终的稳态。

yangqinghui

aznsj 发表于 2024-1-12 15:04
SET initial voltage to the VCO internal nodes.  .ic .... you can also lower your simulator accuracy  ...

i dont know about vco, mine is the crystal osc. you can see the red arrow pointing, i set initial voltage but they are changed at 0~50us.
i think maybe i need to set more and more initial voltage node?

                               
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yangqinghui

esbwong 发表于 2024-1-12 14:57
transient options form -> misc tab. -> additionalParams
linearic=yes oscfreq=

thanks ,the content on the official is exciting, but i failed. i will check the setting. thanks again.

yangqinghui

eelin 发表于 2024-1-12 15:34
给个transient noise

谢谢，但是这个似乎没有用呀。