CMOS active pixel image sensor with in-pixel CDS for high-speed cameras

Abstract

This paper presents a high-speed CMOS image sensor whose frame rate exceeds 2000 frames/sec (fps). The pixel includes a photodiode, a charge-transfer amplifier, and circuitry for correlated double sampling (CDS) and global electronic shuttering. Reset noise, which is the major random noise factor, is reduced by the CDS combined with the charge-transfer amplifier. The total number of devices in the pixel is 11 transistors and 2 MOS capacitors. Test circuits were fabricated using the 0.25 µm CMOS process. The sensitivity of the 20 x 20 µm 2 pixel using the floating diffusion capacitor of 6.2 fF and the photodiode area of 15 x 12.7 µm 2 is 34 V/lux-sec. At 1000 fps, noise level is 2.43 mV rms (dark). The noise level and the sensitivity are greatly improved compared to the non-charge-transfer pixel without global shutter (3Tr-type) implemented with the same technology, and to a previous version of the APS with in-pixel CDS.

Synchrotron-based radioscopy with spatio-temporal micro-resolution using hard X-rays

“…For the ultra-fast digitalization of the scintillator's luminescent image as projected via the optical system we use the novel high-speed camera Photron Fastcam SA-l [22]. The camera's CMOS chip uses 1024 x 1024 pixels, each 20 Jlm in size.…”

Implementation of correlated double sampling circuit on glass applied for active pixel sensing array

“…Correlated double sampling (CDS) is one of the most common used method to eliminate the effect of linear device variations 8,9 . Recently, it is common to realize CDS function in IC by operational amplifier (OPA) and switch capacitors before the signal is transferred to ADC.…”