Abstract
A high dynamic range pixel has been developed for an active-pixel CMOS image sensor, by using a standard 0.25-µm CMOS logic process. The operation method is the same with conventional 3T pixel cell, and applying a control pulse voltage to photo-gate. The experimental results demonstrate that extended dynamic range is obtained when we delay the pulse voltage to apply to photo-gate, and sensing device design also affects dynamic range. So, the high dynamic range can be approached by optimizing pixel design and photo-gate pulse timing. The imaging sensitivity can be improved through optimizing the PG to PD area ratio and the bias pulse high level. The experimental results demonstrate the pixel can achieve both high sensitivity at low illumination and extended dynamic range for high illumination.