A 11-bit ENOB Noise-shaping SAR ADC with Non-binary DAC Array

Successive approximation register analog-to-digital converter (SAR ADC) is an appropriate choice in moderate sampling rate and moderate resolution. If the target of the ENOB is higher than 11 bits, conventional SAR ADC has difficulty in realizing this target. Noise-shaping SAR ADC is a better way to improve the ENOB by shaping the quantizing noise. This paper proposed a modulator based on a 9-bit resolution SAR ADC and used non-binary DAC array to relieve the setup time of the capacitance and reduce the harmonic wave produced by DAC array.