A 128-channel High Precision Time-to-digital Conversion Module

The precise time measurement with less than 100 ps precision is widely used in various fields such as large-scale physics experiments, laser ranging, medical imaging, and so on. In these fields, the time-to-digital conversion (TDC) module requires high accuracy and integration density, and needs to implement more than 100 channels of TDC in a limited area. Considering that the performance evaluation of the module is necessary before being used, manual scanning tests of such a multi-channel system are cumbersome and time-consuming. Therefore, it is necessary to design an on-board self-test function. This work is based on the self-developed TDC chip to design a 128-channel high-precision TDC module with self-test function, which is compatible with the PXI chassis. The test results show that all the 128 TDC channels can achieve a time measurement precision of better than 60 ps RMS, with a good uniformity. In addition, the on-board self-test circuit can generate high-precision test pulses as expected and complete automatic performance evaluation testing.