Paper

Digital Pixel Sensor using Frame Averaging Unit for Fixed-Pattern Noise Correction and Pixel Size Reduction

2025 Jun

Authors Tsung-Hsun Tsai, Raffaele Capoccia, Kwuang-Han Chang, Hao-Ming Hsu, Yi-Hsuan Lin, Chien-Chun Lee, Chiao Liu

Int. Image Sensor Workshop (IISW)

Digital pixel sensors (DPS) have low-power, high dynamic range (HDR), and high-speed capabilities [1]-[8], suitable for applications requiring better performance over that provided by conventional CMOS image sensors. However, integrating an in-pixel analog-to-digital convertor (ADC) in a small pixel size leads to increased fixed-pattern noise (FPN) and degraded low-light performance. While noise reduction can be achieved through digital correlated double sampling (d-CDS) technique in DPS, the additional circuit and memory requirement increases the pixel size. In this work, a frame averaging unit (FAU) is developed to enable on-sensor FPN correction (FPNC) without increasing the pixel size. The developed approach achieves a 3.24-µm pixel size, delivering a temporal noise of 4.4 e-rms and an FPN of 2.4 e-rms.