The size of pixel array in imaging device is getting larger. Beyond the digital still camera, image sensors are widely used in digital cinema and digital broadcasting system. Digital still camera above ten millions pixels is already commercialized. In digital broadcasting area, two megapixels HDTV is already into practical use, and eight megapixels HDTV is considered as next generation format. UDTV, which has nearly ten million pixels is under active technology development. As the number of pixels are increased, some undesirable effects like IR drop in power/ground line should be considered and more design efforts for speed and power consumption becomes required in design of CMOS image sensors.

We developed integrated readout circuit and analog-to-digital converters for megapixel CMOS image sensor. We implemented demonstration chip with 1.3 millions pixels. The demonstration chip is fabricated with 0.18 µm CMOS process and has 3.0 µm pixel pitch.

Figure 1. Sample Images