Design and Simulation of High Event Rate and High Precision TDC ASIC Prototype for Pixel Detector

The pixel detector has been widely used in the inner track detector of high energy particle physics experiments because of its excellent position resolution. With the development of physics experiments, many experiments require detectors and readout electronics to have the capability of high-precision time measurement. To reach the requirement of pixel detectors about the time measurement, a TDC(Time-to-Digital Conversion) ASIC(Application Specific Integrated Circuit) prototype with high event rate processing capability and high precision has been designed. It is expected to be integrated with the front-end readout ASIC of pixel detector as a core component in the future. TDC presented in this paper adopts the combination of coarse and fine measurement, in which the coarse time measurement is based on the counter, and the fine time measurement is implemented by employing the architecture of TAC(Time-to-Amplifier Converter) combined with ADC(Analog-to-Digital Converter). The prototype circuit has been designed based on 130 nm process. TDC has also been simulated, the simulation results indicate that the circuit has the capability processing up to 11 consecutive events in which the time interval between adjacent events is as small as 500 ps, while the bin size of TDC is 2 ps, the DNL (Differential Non-Linearity) is less than 2.8 ps, and the time measurement precision is better than 5 ps RMS.