Impact of Radiation-Induced Single-Event Transients on High Resolution Time to Digital Converter

The paper presents the analysis of radiation-induced Single-Event Transients (SET) in Delay-Locked Loop (DLL) and its impact in the digital output of Time-to-Digital Converter (TDC). The performance of the TDC such as Differential Non-Linearity (DNL), Integral Non-Linearity (INL), resolution etc. are degraded due propagation of the SET from the DLL. The use of improved pseudo differential current-starved delay cell structure in the Voltage Controlled Delay Line (VCDL) in DLL reduces the impact of radiation-induced SET in DLL, and enhances the robustness of DLL based TDC. This effort represents the first of its kind SET analysis on a DLL based TDC. The proposed DLL based TDC is designed in the AMS 180 nm CMOS technology and simulations show that the number of missing pulses on a SET strike in the modified pseudo differential delay cell is reduced to 50% than compared the conventional architectures.