The disclosure is directed to low-power high-resolution analog-to-digital converter (ADCs) circuits implemented with a delta-sigma modulators (DSMs). The DSM includes a single-bit, self-oscillating digital to analog converter (SB-DAC) and a dual-slope integrating quantizer that may replace an N-bit quantizer found in a conventional DSM. The integrating quantizer of this disclosure oscillates after quantization because the SB-DAC in the feedback path directly closes the DSM loop. The integrating quantizer circuit includes a switch at the input and two phases per sample cycle. During the first phase the switch sends an input analog signal to an integrator. During the second phase, the switch sends the feedback signal from the output of the self-oscillating SB-DAC to the integrator. The input to the SB-DAC may be output from a clocked comparator.