Infrared focal plane array (IRFPA) is a key component in infrared system and thermal imaging devices, widely applied in military and civilian fields, with a huge market potential and prospects. IRFPA readout circuit technology and test technology in its research occupies an important position, related to the ability to accurately and efficiently obtain the IRFPA signal and the ability of IRFPA devices for accurate performance evaluation. This paper uses an IRFPA point-by-point bias calibration, through a series of accurate timing control signals to read and save the calibration data and external input, effectively increases the point-by-point bias control accuracy, and finally improves the quality of the output image.
This paper designs a ramp generating circuit using for uncooled infrared focal plane arrays (UIRFPA). Compared with the basic ramp generator, the new generator is highly adjustable, easy to operate, and adaptable. By adjusting the total current of the charging circuit, it can realize the ramp wave upper point and slope of the modulation. Current mirror as the discharge load, it can adjust the ramp lower point, and controllable capability. By adjusting accuracy and swing, the new ramp generator for UIRFPA provides a way to adapt to the strength of the infrared scene to control the infrared signal accuracy. Simulation results show that the ramp output swing can be adjusted from 1 V to 4.5 V, a maximum Integral nonlinearity (INL) of 400 µV, a slope distortion lower than 0.01%, linearity higher than 13 bits for the new ramp generator (considering a 4 V input range). At the same time, its good temperature performance shows that the maximum difference of the output voltage is 50 mV in a variety of environments (243 K ~ 333 K). Besides, this circuit has been successfully applied to the infrared system.