Comparison of modern CCD and CMOS image sensor technologies and systems for low resolution imaging

CMOS image sensors were introduced to the market in 1995 and in the past three years have taken significant market share from CCD sensors in the low-end digital camera markets (e.g., web cams). CMOS sensors boast low power dissipation, single supply operation and camera-on-a-chip integration, and CCD sensors boast high sensitivity and low noise. The sensors are based on inherently similar technologies (silicon photodetectors and CMOS read-out electronics); therefore one would expect they share the same fundamental limits. We analyze CMOS and CCD detector systems from the architecture down to the sensitivity of the pixel and read-out electronics. Our analysis shows that for low resolution imaging (VGA and below) CCD and CMOS sensor technologies are converging to practically indistinguishable solutions in terms of performance, size and cost.