I have some problem with a transient simulation with the AD8227 and LTSPICE..
Running the supplied test fixture is no problem, but when the common mode voltage and the Ref voltage is set to 0 the simulation stops.
As LTspice is now ANALOG this sholud be a valid question.
Try adding this statement in the schematic ".options cshunt=1e-15" to solve the convergence problem of this condition on the model.
This link will help you understand more on this convergence…