Recent Developments and Design Challenges of High-Performance Ring Oscillator CMOS Time-to-Digital Converters

Time-to-digital converters (TDCs) are increasingly used as building blocks in biomedical imaging, digital communication, and measurement instrumentation systems. When fabricated in deep-submicrometer (DSM) CMOS technology, TDCs have outstanding time stamping capability on the order of picoseconds. Typically, the timing resolution of a TDC directly determines the minimum resolvable spatial resolution in time-of-flight (ToF) measurements. It also …