320×256中波红外焦平面器件低噪声采集系统设计

Acquisition System with Low Noise Based on 320×256 Medium Wavelength Infrared FPA

根据320×256中波红外焦平面器件内部电路结构特点以及输出微弱模拟信号的特点,系统从低噪声和抗干扰的角度出发,设计了由电源模块、驱动电路、A/D转换电路、数据处理电路、时序控制模块等模块组成的低噪声中波红外焦平面图像数据采集系统。通过噪声测试和成像实验得到,在26℃的室温下,测得的电路噪声为0.1 m V,在1000?s积分时间时系统噪声1.5 m V,各个像元的SNR在62~65 d B之间。

This paper provides a description of the signal processing design procedure for an acquisition system with low noise, using the internal circuit structure characteristics and output analog signal characteristics of a 320 ×256 medium wavelength infrared FPA. A medium wavelength infrared FPA image data acquisition system consists of a power supply module, drive circuit, A/D conversion circuit, data processing circuit, and sequential control module. Through noise tests and imaging experiments, the circuit’s noise is found to be approximately 0.1 mV and the system’s noise is approximately 1.5 mV at 26℃（room temperature）. A pixel’s signal-to-noise ratio （SNR） is between 62 dB and 65 dB. The results show that the system has good noise characteristics and that it can meet the requirements of practical engineering applications.