Noise model, analysis and characterization of a differential active pixel sensor

We report the design, analytical model and experimental noise performance from a photo sensor fabricated in a 0.5 mu m commercial CMOS process. The sensor is a novel differential active pixel sensor which performs in-pixel correlated double sampling (CDS) to reduce correlated and environmental noise at the expense of increased thermally generated noise sources such as reset and readout noise. In comparison with a representative single ended sensor, the differential sensor exhibits an increased fundamental reset and readout noise of 117% and 58% respectively.