Abstract: In accordance with an embodiment, a method of operating an oversampled data converter having a switched-capacitor (SC) integrator includes operating the oversampled data converter in a gain calibration mode; applying a first voltage to a feedback port of the SC integrator to form a feedback voltage, and during a first clock phase the method further includes applying the first voltage to a first series capacitor via the input port when an output of the oversampled data converter is in a first state; applying a bypass voltage to the first series capacitor when the output of the oversampled data converter is an a second state and applying the first voltage to a second series capacitor via the feedback port with a polarity based on the output of the oversampled data converter, and during a second clock phase the method includes integrating charges of the first series capacitor and the second series capacitor.