UMC 180 nm process capacitors

[bestvlsi]

Hi All,

I am making a ckt in which i have to use a capacitor. Now the options i am having is NCAP_MM and PCAP_MM . Can anyone tell which one of these two has lower process variation.

Regards.

 

[jimito13]

The best way to evaluate the performance of a process capacitor is to create your own testbench and run Monte Carlo or process' corner simulations.
So,create a schematic with just one capacitor (firstly with NCAP_MM and secondly with PCAP_MM).Connect a port (configured as DC at it's properties' CDF form) from analogLib to the left pin of the capacitor and the right pin to an ideal ground (gnd symbol from analogLib).The middle pin of the capacitor should be connected to the respective substrate node (sub! or wherever else your process suggests in order to perform a realistic connection with the substrate and make your simulation more confident and accurate).Now,run S-Parameters (SP) analysis (over process' corners or Monte Carlo with the process variation option enabled) from ADE L and make use of the magnitude of the Y-Parameters results.

Remember that :

(1/|Y11|)=(1/ωC)=>|Y11|=ωC=>C=|Y11|/2πf.

The f frequency variable can be obtained with the usage of the xval function available in the calculator.