School of Electronics Engineering, Kyungpook National University, Daegu 41566, Korea.
Korea Electronics Technology Institute, Seongnam-si 13509, Korea.
Sensors (Basel). 2019 Apr 6;19(7):1653. doi: 10.3390/s19071653.
In this paper, we propose an averaging pixel current adjustment technique for reducing fixed pattern noise (FPN) in the bolometer-type uncooled infrared image sensor. The averaging pixel current adjustment technique is composed of active pixel, reference pixel, and calibration circuit. Polysilicon resistors were used in each active pixel and reference pixel. Resistance deviation among active pixels integrated with the same resistance value cause FPN. The principle of the averaging pixel current adjustment technique for removing FPN is based on the subtraction of dark current of the active pixel from the dark current of the reference pixel. The subtracted current is converted into the voltage, which contains pixel calibration information. The calibration circuit is used to adjust the calibration current. After calibration, the nano-ampere current is output with small deviation. The proposed averaging pixel current adjustment technique is implemented by a chip composed of a pixel array, a calibration circuit, average current generators, and readout circuits. The chip was fabricated using a standard 0.35 μm CMOS process and its performance was evaluated.
本文提出了一种用于降低测辐射热计型非制冷红外图像传感器中固定模式噪声（FPN）的像素电流平均调整技术。该像素电流平均调整技术由有源像素、参考像素和校准电路组成。每个有源像素和参考像素中都使用了多晶硅电阻。集成了相同电阻值的有源像素之间的电阻偏差会导致 FPN。用于去除 FPN 的像素电流平均调整技术的原理基于从有源像素的暗电流中减去参考像素的暗电流。减去的电流被转换为电压，其中包含像素校准信息。校准电路用于调整校准电流。校准后，以较小的偏差输出纳安电流。所提出的像素电流平均调整技术是通过一个由像素阵列、校准电路、平均电流发生器和读出电路组成的芯片来实现的。该芯片采用标准的 0.35μm CMOS 工艺制造，并对其性能进行了评估。
