LAUSR

One of the most important functional units in digital circuitry for synchronization and measurement is time-to-digital converter (TDC) which always requires higher resolution and accuracy. In this brief, a process, voltage, temperature (PVT)-variation-insensitive TDC featured with a PVT detector is proposed. The PVT detector takes advantage of another delay line with optimized locking conditions to differentiate PVT corners. The proposed TDC is physically realized using a 90-nm CMOS process. On-silicon measurement results demonstrate 30-ps resolution, < 1.5 LSB INL/DNL, and 2.22 mW at 100 MHz and 1.2-V supply voltage.