slew rate simulation question

[chungming]

Hi~~
i have a question about how to simulate slew rate in fully differential switched cap CMFB OPA?
like attached file
Why using 1M Ohm? is more larger more better?
and why using 6.8pF cap as unit gain , why don't use other number?
thanks~~!!

 

[Material]

I guess 6.8p capacitor may be the requirement of your system.
Too big resistor will degrade the cm voltage on input node for the reason of voltage division.

 

[rajanarender_suram]

i dont understand ur schematic. is the (diff OPAMP) block shown is the ideal or practical model/ or it is a schematic???

 

[pkalavakuru]

Hallo


If u want to see the result in Transient simulation ..u have to take the difference of the two outputs then u'll real out put

ciao