A 6-b 400 MSPS CMOS folding and interpolating ADC

This paper describes a 6-b 400 MSPS CMOS folding and interpolating(F&I) ADC. To overcome the delay difference of an MSB part and an LSB part in a typical F&I ADC the ADC is composed of only one LSB part and to alleviate the offset voltage of comparators in the LSB part preamplifiers are used in front of the comparators. This paper analyzes a folder and presents a design procedure of the folder. The ADC has the DNL of 0.3 LSB and the INL of 0.6 LSB and consumes the power of 120mW $$ 3 V. The ADC is designed in a 0.6 $\mu\textrm{m}$ CMOS process.