10-ps Resolution hybrid time to digital converter in a 0.18 μm CMOS technology

Abstract

This paper presents a new Time to Digital Converter (TDC) design that combines the traditional Analog Time to Amplitude Converter (TAC) and Digital TDC techniques to obtain a very high adjustable time precision that could reach 10ps with a maximum dynamic range of 10 μs a DNL of 0.4 LSB a dead time of 15 ns. The proposed new “hybrid TDC” concept was used to design an array of 8 time interval measurement units for a Time correlated single photon counting(TCSPC) system in a 0.18 μm CMOS technology. The common Delay locked loop (DLL) and coarse counter approach makes the design flexible and easily scalable allowing the conception of larger TDC arrays without the need to implement several DLLs.