Noise analysis of imagers with a-Si:H pin diode pixels

We propose a comprehensive noise analysis for a-Si:H pin diode pixels in thin film on application specific integrated circuit (ASIC) image sensors. Signal-to-noise (SNR) ratio and dynamic range (DR) at the input of the pixel amplifier are calculated with shot and flicker noise of photocurrent and dark current and the thermal noise of the pin diode parallel resistance. The effect of the thermal noise of the pin diode series resistance under consideration, of the dynamic systems properties of pin diode and pixel amplifier, and of reset noise are included. The thermal noise of the series resistor is the largest source of thermal noise at the input of the pixel amplifier. The effect of the decreasing pixel area when scaling down the technology on feature sizes is discussed. The noise analysis is presented for a high resolution imager.