Experimental Comparison of Four Different CMOS Pixel Architectures Used in Indirect Time-of-Flight Distance Measurement Sensors

Abstract

Four different pixel architectures to be used in CMOS based indirect time-of-flight (ToF) rangers were designed, fabricated and characterised. The measured results are presented here for their direct comparison. Sharing a very similar, yet case optimised readout circuitry in each case, three fabricated CMOS rangers were based respectively on a pinned photodiode (PPD), a photogate, and a newly developed CMOS intrinsic lateral drift-field photodiode (LDPD), having a 40µm pixel pitch in each case, and finally compared to the pixel configuration based on a CMOS standard n-well based photodiode (PD). In all four cases, ranging is based on pulsed laser illumination and indirect time-of-flight measurements.