A 35µW 96.8dB SNDR 1 kHz BW multi-step incremental ADC using multi-slope extended counting with a single integrator

A multi-step incremental ADC (IADC) with multi-slope extended counting is presented. In the proposed IADC, the accuracy is enhanced by reconfiguring it as a multi-slope ADC in two additional steps. For the same accuracy, the conversion cycle is shortened by a factor of about 2
⁹
as compared to the single-step IADC. Fabricated in 0.18-μm CMOS process, the prototype ADC operates at 642 kHz and achieves a peak SNDR = 96.8 dB and DR = 99.7 dB over a 1 kHz bandwidth. The power consumption is 35 μW, which results in an excellent Schreier FoM of 174.6 dB.