Can we use MOM capacitors to built the DAC capacitor array in a SAR ADC?

[howardtang85]

HI all,

I have just done a single MOM capacitor extraction. I found that the top plate of the MOM capacitor has quite a huge parasitic capacitance (about 5% of its own capacitance, and bottom plate is even worse). Therefore, I am wondering if MOM capacitors can be used to form the capacitive DAC of a SAR ADC? Would the charge-redistribution effect be affected by these parasitic capacitance since the output is always connected to the top plate of the capacitors.

 

[leo_o2]

It depends on your circuit structure and design specification. You could add this parasitic cap in your simulation to check if requirement is satisfied or not.