A 60fps9.9nJ/frame·pixel CMOS Image Sensor with On-Chip Pixel-wise Conversion Gain Modulation for Per-frame Adaptive DCG-HDR Imaging

High dynamic range (HDR) features are highly desired in high-end mobile CMOS image sensor (CIS) products. For dual conversion gain (DCG) based HDR applications, however, CISs suffer from frame rate reduction and higher power consumption. In this paper, we introduce a CIS design with per-frame pixel-wise conversion gain (CG) modulation. A prototype CIS with a resolution of $512\times 320$ achieved a 90.5dB dynamic range, and 9.9nJ/frame·pixel of power FoM. Compared to conventional DCG-HDR imaging, at 60fps, the proposed adaptive DCG-HDR imaging reduced CIS power consumption by 38% and enabled single-frame pixel-wise HDR for future mobile CIS products.