A 0.75V CMOS image sensor using time-based readout circuit

This paper proposes a low-voltage CMOS image sensor (CIS) using time-based readout (TBR) circuit. This TBR circuit reads out the moment of event from pixel instead of the voltage signal. This allows the use of low supply voltage in pixel with sufficient signal range. The prototype chip was fabricated with a 0.13-µm standard CMOS process and whole circuit uses thin-oxide gate transistors only. The measurement results show 54.2-dB dynamic range and 1.6-µW pixel power consumption in 0.75-V supply voltage. The fill factor is 38% in 3.4-µm pixel pitch.