This study proposes a $368\times184$ optical under-display fingerprint sensor designed and prototyped using the 0.11- $\mu \text{m}$ CIS technology. The prototype sensor includes a hybrid array of global and rolling shutter pixels and a shared pixel-level analog-to-digital converter (ADC) embedded in a 32-pixel subarray configuration. It features a fast response time and low power consumption. By directly coupling the ramp signal to a floating diffusion capacitor with shared pixels, the best compromise between full-well capacity (FWC) and conversion gain is achieved. Two sets of memory (184 $\times $ 92 bytes) are also embedded in the pixel array to save the costs of external memory. A dynamic range of 110 dB is achieved with eight-segment automatic exposure and a contrast enhancement scheme for black level correction. A pixel binning process is used to improve the sensor sensitivity. The measured FWC, sensitivity, and conversion gain are 95 ke-, 800 ke-/lux-s, and $340~\mu \text{V}$ /e-, respectively. The prototype fingerprint sensor consumes only 15 mW with a 3.3-V supply voltage. The sensor chip size is 9.74 mm $\times \,\, 4.6$ mm, and the sensing area is 8 mm $\times \,\, 4$ mm, which is 71.4% of the chip size. The resolutions of the sensor without and with the pixel binning process are 1154 and 572 dpi, respectively.

中文翻译：

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368×184光学下显示指纹传感器，包含全局像素和滚动快门像素的混合阵列以及共享的像素级ADC

这项研究提出了 $ 368 \次184 $ 使用0.11设计和原型化的光学式显示屏下指纹传感器 $ \ mu \ text {m} $ CIS技术。原型传感器包括全局和滚动快门像素的混合阵列，以及嵌入在32像素子阵列配置中的共享像素级模数转换器（ADC）。它具有快速响应时间和低功耗的特点。通过将斜坡信号直接耦合到具有共享像素的浮动扩散电容器，可以在全阱容量（FWC）和转换增益之间取得最佳折衷。两组记忆（184 $ \次$ 92字节）也嵌入像素阵列中，以节省外部存储器的成本。通过八段自动曝光和用于黑电平校正的对比度增强方案，可以实现110 dB的动态范围。像素合并处理用于提高传感器灵敏度。测得的FWC，灵敏度和转换增益分别为95 ke-，800 ke // lux-s和 $ 340〜\ mu \ text {V} $ / e-。原型指纹传感器在3.3V电源电压下的功耗仅为15mW。传感器芯片尺寸为9.74毫米 $ \ times \，\，4.6 $ 毫米，感应面积为8毫米 $ \ times \，\，4 $ 毫米，占芯片尺寸的71.4％。没有像素合并过程和带有像素合并过程的传感器的分辨率分别为1154和572 dpi。