A 12-/14-bit, 4/2MSPS, 0.085mm² SAR ADC in 65nm using novel residue boosting

In this paper, a re-confîgurable 12/13/14-bit SAR ADC based on a 12-bit ADC core is presented. A novel residue-boosting algorithm is developed to increase the bit resolution of a SAR ADC up to 2 bits without significant additional area and power. In the 12-bit mode, the 65nm prototype shows both DNL and INL of about +/−0.5 LSB at 4MSPS, and in 14-bit mode, DNL and INL are about +/− 1 LSB and +/− 2 LSB at 2MSPS. ENOB is 11.5 bit and 13 bit for 12-bit and 14-bit mode each. The area of the ADC is 0.085mm ² .