question abt the offeset of differntion outpur opamps

[manissri]

how to calculate the offset voltage of fully differential (differntinal input and differntional output)
as i read in therry that there should be no offset in differentiaal output opams
please clarify

 

[renwl]

there are mismatchs too.
so there are offset in differentiaal output opams too.

 

[PaloAlto]

Every transistor has equivalent offset sources, put them in the circuit and transfer them to the input, you will see the dependence of the offset every component.

But, in the end it will be the input pair equivalent offset + the load of this pair attenuated by its gain + in a every time smaller contribution, the rest of the circuit.