Delta sigma ADC with output tracking for linearity

An exemplary circuit includes a tracking circuit, a current estimator, a switch control logic, and a switching load circuit. The tracking circuit tracks a digital output signal of a delta-sigma modulator (DSM) and provides a tracking signal representing an average of the digital output signal during a time period. The current estimator determines an amount of loading to be applied to positive and negative reference voltages based on the tracking signal. The switching load circuit is coupled to positive and negative reference voltages of the DSM, the switching load circuit connects a selected amount of loading to the positive and negative reference voltages in response to a control signal to balance a reference load current applied to the DSM. The switch control logic provides the control signal to the switching load circuit based on the determined amount of loading to be applied to the positive and negative reference voltages.