A sigma-delta converter, analog-to-digital conversion system, and an Integrated Circuit (IC) chip are disclosed that include a main sigma-delta modulator and an auxiliary sigma-delta modulator. The auxiliary sigma-delta modulator is electrically matched with the main sigma-delta modulator and is configured to generate an output that is incorporated into a feedback loop of the main sigma-delta modulator to enable the main sigma-delta modulator to adjust an offset signal applied at a main analog channel.