It is my first time trying to use pz analysis tool in IC514, so I created a very simple testbench including a simple miller OTA and an ideal svsvs having 1 pole. I got some issues and 3 points to be enlightened :
- First, when there is only the svcvs in the testbench, the pz summary give the expected result (only one pole). However, when I add the miller OTA in the testbench, the pz summary for the same svcvs give a lot of pole and zero (more than 20) additionnal to the expected pole. However, I noticed that most of them cancel each others. My question is why this happen, even if the only common node between th 2 blocks is VSS ?
- hence, the second question is how can I display only the pole and zero that are not cancelled ?
- Third, how to define the right component eval freq, as the MOS are frequency dependent component and the result varies with the eval freq I specify?