A high sensitivity correlation image sensor

Abstract

The correlation image sensor (CIS) is an important device for detection of modulated light signals at high frame rates. In this paper a demodulation pixel is presented which increases the sensitivity of the CIS device. The pixel is capable of detecting and demodulating light signals at lower illumination levels compared with the previous designs. Furthermore due to the low number of processing stages the random noise at the output remains close to the kT/C reset and photodiode shot noise. The presented design is compared with previous solutions under similar operating conditions using a 0.35µm standard CMOS technology. It is shown that while the fill factor and power consumption of the design is close to the previous structures, it is able to operate at lower modulated illumination levels and higher dynamic range of background intensities.