System level modeling is applied to a recently proposed indirect current feedback (ICF) chopper instrumentation amplifier based on a Gm-C low pass filter architecture. The aim of the study is solving important limitations of the previous architecture in terms of output range and bandwidth-to-chopper frequency ratio. The possibility of obtaining a rail-to-rail input common mode range is also investigated. An improved architecture is proposed and analyzed by means of simulations that consider the main non-idealities of the building blocks.