Abstract :
The measurement of time intervals with high resolution, precision, and
stability on a large number of channels has been used in a multitude of large-scale
scientific experiments in particle and nuclear physics. In the early 1950s,
however, no standard instruments were available to measure time intervals
with subnanosecond time resolution for such scientific experiments. The novel
Vernier chronotron proposed in the 1950s by Emilio Gatti [1], based on two
oscillators at slightly different frequencies, was an important step toward
future detectors and instrumentation able to access high-resolution time measurements
in the ps domain. During the 1960s and 1970s, further novel time-to-digital
converter (TDC) architectures were developed, and several of these were used
until the 1980s in standard modular instrumentation modules, including those
based on the Nuclear Instrumentation Module (NIM), Computer Automated Measurement
and Control (CAMAC), IEEE Fastbus, and Versa Module Eurocard (VME) standards.
At the end of the 1980s, the required number of TDC channels in high energy
physics (HEP) experiments increased rapidly, reaching the tens <?Pub Caret?>and
hundreds of thousands of measurement channels. This gave rise to the development
of various fully integrated, multichannel TDC application specified integrated
circuits (ASICs) for use in HEP [2], [3].
