A Self-Calibrating Sub-Picosecond Resolution Digital-to-Time Converter

A novel self-calibrating high-resolution digital-to-time converter (DTC) achieves 1024 individual phase states with a resolution of 0.5 ps. The phase interpolation is done in steps, by using a cascade of coarse active delay locked line and a passive programmable fine delay. The DTC is capable of self-calibration by using an integrated dual mixer time domain (DMTD) circuit to overcome device mismatch and process variations. The DTC is constructed using 90 nm standard digital CMOS technology at 1 GHz RF frequency. Future improvements are expected to increase the resolution to 0.1 ps and below.