TKO 32-channel pipeline TDC module using a 1 GHz GaAs shift register

A high-density, high-speed pipeline TDC (time-to-digital converter) that operates at a 11-GHz clock frequency has been developed. The depth of each internal shift register is 256. Special GaAs shift register and GaAs clock controller/driver ICs were developed for this module. Operating at 1-GHz clock speed, it can provide a time resolution of 0.4 ns (RMS) and a time range of 256 ns. This module is also a reasonably low-power unit for its class due to an inherent property of GaAs ICs. This pipeline TDC module is at the mass-production stage and will be used for a KEK experiment starting at the end of 1990. The pipeline nature of the TDC provides multihit capability, which is essential for experiments with a high hit rate on each detector channel