A 9b, 1.25ps Resolution Coarse-Fine Time-to-Digital Converter in 90nm CMOS that Amplifies a Time Residue

A 9 b 1.25 ps two step time-to-digital converter is implemented in 90 nm CMOS. It uses a new circuit to amplify the time residue, and compensates mismatch with subrange normalization. DNL and INL are, respectively, plusmn0.8 LSB and plusmn2 LSB. It can be used as a phase detector with digital output.