Spiking Pixel

Science China publishes a letter "A variable threshold visual sensing and image reconstruction method based on pulse sequence" and supplementary materials by Jiangtao XU, Peng LIN, Zhiyuan GAO, Kaiming NIE & Liang XU from Tianjin University and Tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology.

"Pulsed-based CMOS image sensor (CIS) outperforms classic CIS in terms of data rate, and is able to achieve ultra-highspeed imaging. A pulsed-based CIS which is able to capture the movement of the hard disk rotating at 6000 r/min, was designed in our previous work.

The structure and working process of the spiking pixel based on variable threshold are shown in Figure 1. The threshold curve consists of periodic ramps. Each ramp consists of many small steps, whose width is set equal to frame period Tu and height is written as Vs. The threshold voltage linearly increases from minimum value Vth0 to maximum value Vth,max by step height Vs every frame cycle during a ramp cycle. Every time a new ramp cycle starts, a ramp pulse is output by a global ramp generator."