A Novel Compact Time-To-Amplitude Conveter for Spad Detector

This paper presents a novel compact time-to-amplitude converter (TAC) architecture for offering the potential to reduce occupation area and increase fill-factor (FF) of single photon avalanche diode (SPAD) pixel. To meet requirement of high FF and large SPAD array integration, only 16 MOSFETs together with a small timing-capacitor of 80fF are utilized to implement the compact TAC in 180nm CMOS technology. The design achieves high FF of 23.59%, low static power dissipation of 3.19μW and low differential non-linearity in the range of -0.2 to 0.2LSB with full-scale range of 80ns.