A spike based 3D imager chip using a mixed mode encoding readout

Spike based imagers commonly use either time-to-first spike (TTFS) or spike rate encoding exclusively. In this paper we discuss the benefits of using a mixed-mode encoding scheme backed by theoretical analysis and SPICE simulations. The mixed-mode readout uses both TTFS and spike rate information to estimate the illumination for each pixel, which lessens the maximum spike rate and timing clock speeds required for a given level of accuracy. We intend to test this methodology on a generic spike based imager chip we have designed and submitted for fabrication in a 0.13μm 3D SOI CMOS process. The imager is capable of both TTFS and spike rate encoding and should allow us to fully validate our theory.