A circuit system including an operational amplification circuit is disclosed. The operational amplification circuit includes N stages of operational amplification units that are cascaded, an input terminal of the 1st stage of operational amplification unit is an input terminal of the operational amplification circuit, and an output terminal of the Nth stage of operational amplification unit is an output terminal of the operational amplification circuit; an output terminal of the ith stage of operational amplification unit is connected to an input terminal of the (i+1)th stage of operational amplification unit, so as to provide an input signal for the (i+1)th stage of operational amplification unit; and there is a feedback channel from the output terminal of the Nth stage of operational amplification unit to an input terminal of each of the 1st stage of operational amplification unit to the Nth stage of operational amplification unit.