A 1/13-inch 30fps VGA SoC CMOS image sensor with shared reset and transfer-gate pixel control

This paper presents a VGA 1/13-inch system-on-chip (SoC), primarily targeted for the consumer camera mobile phone market. In this market low cost, ease of product integration, low module height, and low light image quality are important features. The SoC simplifies integration of the sensor into the final product by providing camera functions such as: automatic exposure control, automatic white balance, flicker detection and avoidance, etc. This reduces cost and saves power since no companion chip is required, and the internal image-processing data rate of the SoC is higher than the output data rate [1], which keeps the inter chip communication data rate as low as possible. The small optical format enables a low camera module height. However, the choice of the small optical format also restricts the pixel pitch to 1.75μm, which influences both image quality and die size. The low light image quality, in this sensor, is improved by incorporating a 1.75μm pixel architecture, and the size of the sensor core is greatly reduced by removing the dark pixel reference rows and columns, using a single side dual bank of double-pitch sampling capacitors, a class-AB pro grammable-gain amplifier (PGA), followed by an inter-stage shared pipeline ADC.