High dynamic range readout architecture for SPAD array

In this paper, a novel readout method to enhance the readout dynamic range of pixel based on single photon avalanche photodiode (SPAD), is presented. This method overcomes the limitation of existing methods by using a double readout technique based on both time and amplitude measurements without decreasing the fill factor. Another advantage of the proposed method is that this improvement on the dynamic range is achieved without adding extra electronics. The proposed architecture of pixel is based on analog counter.