An operational amplifier circuit (100, 100') with DC offset suppression, comprising: a first operational amplifier comprising: an input stage configured to receive differential input signals (i_p, i_n); and an output stage coupled to the input stage and configured to output a pair of differential output signals (out_p, out_n); and a pair of feedback circuits (120, 130, 120', 130') coupled to the output stage of the first operational amplifier, wherein each of the pair of feedback circuits (120, 130, 120', 130') comprises a differential amplifier (140, 150) comprising a first input end (E41, E51) directly coupled to the output stage to directly receive a corresponding one of the pair of differential output signals (out_p, out_n), a second input end (E42, E52) configured to receive a reference voltage (ref), and an output end (E43, E53) coupled to an end of a corresponding one of a pair of capacitors (C1, C2) and to a gate end of a corresponding one of a pair of bias transistors (M25, M26) of the output stage, to output a corresponding one of a pair of feedback signals (fb1, fb2) responding to a difference between the reference voltage (ref) and the corresponding one of the pair of differential output signals (out_p, out n); wherein the pair of bias transistors (M25, M26) is configured to generate a pair of first bias currents (Ib1, Ib2) of the output stage, so that one of the pair of first bias currents (Ib1, Ib2) is adjusted based on a first feedback signal of the pair of feedback signals (fb1, fb2), and another of the pair of first bias currents (Ib1, Ib2) is adjusted based on a second feedback signal of the pair of feedback signals (fb1, fb2), so that a DC offset of one of the pair of differential output signals (out_p, out_n) is reduced based on the first feedback signal instead of the second feedback signal, and a DC offset of another of the pair of differential output signals (out_p, out_n) is reduced based on the second feedback signal instead of the first feedback signal. a first operational amplifier comprising: an input stage configured to receive differential input signals (i_p, i_n); and an output stage coupled to the input stage and configured to output a pair of differential output signals (out_p, out_n); and an input stage configured to receive differential input signals (i_p, i_n); and an output stage coupled to the input stage and configured to output a pair of differential output signals (out_p, out_n); and a pair of feedback circuits (120, 130, 120', 130') coupled to the output stage of the first operational amplifier, wherein each of the pair of feedback circuits (120, 130, 120', 130') comprises a differential amplifier (140, 150) comprising a first input end (E41, E51) directly coupled to the output stage to directly receive a corresponding one of the pair of differential output signals (out_p, out_n), a second input end (E42, E52) configured to receive a reference voltage (ref), and an output end (E43, E53) coupled to an end of a corresponding one of a pair of capacitors (C1, C2) and to a gate end of a corresponding one of a pair of bias transistors (M25, M26) of the output stage, to output a corresponding one of a pair of feedback signals (fb1, fb2) responding to a difference between the reference voltage (ref) and the corresponding one of the pair of differential output signals (out_p, out n); wherein the pair of bias transistors (M25, M26) is configured to generate a pair of first bias currents (Ib1, Ib2) of the output stage, so that one of the pair of first bias currents (Ib1, Ib2) is adjusted based on a first feedback signal of the pair of feedback signals (fb1, fb2), and another of the pair of first bias currents (Ib1, Ib2) is adjusted based on a second feedback signal of the pair of feedback signals (fb1, fb2), so that a DC offset of one of the pair of differential output signals (out_p, out_n) is reduced based on the first feedback signal instead of the second feedback signal, and a DC offset of another of the pair of differential output signals (out_p, out_n) is reduced based on the second feedback signal instead of the first feedback signal.