A system, comprising: a sigma-delta modulator using an integrator of a cascade-of-integrator feedback topology to perform operations is disclosed. The operations can comprise in response to receiving a gain value, applying the gain value to a group of feed-forward coefficients, determining a change in the gain value, and adjusting, during a clock cycle of a defined time period, a plurality of state variables of the sigma-delta modulator by multiplying each of the state variables by the scale factor that is a ratio of the gain value after determining the change in the gain value the gain value before determining the change in the gain value.

A delta-sigma analog-to-digital converter is provided that includes a continuous-time integration stage having an input terminal coupled through a switch to an input resistor that in turn couples to an input signal node. A feedback digital-to-analog converter converts a digital output signal to form a feedback current that also couples to the input terminal. A controller switches the first switch responsive to a duty cycle of the feedback current.

A nested - analog-to-digital conversion system and method, compromising: an analog filter, an analog comparator, a first feedback digital-to-analog converter (DAC), a second feedback DAC placed in front of the first feedback DAC, and a digital filter and an MSB quantizer placed at the output of the analog comparator; wherein the input of the first feedback DAC is connected to the output of the analog comparator; the analog filter, the analog comparator, and the first feedback DAC form an internal analog - loop; the input of the second feedback DAC is connected to the output of the MSB quantizer; the output of the second feedback DAC is connected to the output of the first feedback DAC and to the input of the analog filter; and the second feedback DAC, the internal analog - loop, the digital filter, and the MSB quantizer form an external hybrid - loop.