The Readout Integrated Circuit Of Uncooled Infrared Focal Plane Array Base On Fpga

Uncooled infrared focal plane imaging technology becomes increasingly concerned as the cost of the devices and systems is low, the volume is small and the cooling system is unnecessary. Pyroelectric materias are potential candidates for uncooled infrared focal plane. Compared with other pyroelectric materias, (Ba1-xSrx)TiO3 (BST) possesses high pyroelectric coefficient, dielectric constant, low loss and good compatibility, so it has became the focus of scientists. This thesis is focus on the read-out circuit of BST infrared detector.The thesis introduces the research purposes, history and classification of infrared detector. The read-out circuit is one of the most important parts of infrared detection technology. In the thesis, we analyze the advantages and disadvantages of several kinds of read-out circuits and consider the detection principle of BST, we choose BH5001 chip as the core device of the preamplifier circuit. Then we use FPGA to deal with the siginal of the preamplifier circuit which containes the parts of signial analysis, timing control, display system and alarm system. To ensure the device work properly, we use Quartus II to simulate, compile and synthesize the signals.Testing the capacitance with our circuit, compared with the digital bridge, the relative error is less than 0.86%. The result showes that the circuit could measure the capacitance accurately. The circuit could detect the infrared signal when BST was accessed and exposed under the black body (500k) infrared signal, and the value was about 2pF, at the same time the buzzer was given alarm signal, so the circuit could accomplish the function reading the sign from BST detector. The capacitance-temperature curve measureed by our circuit is consistent with the dielectric constant- temperature curve. The detection of the infrared radiation and the data acquisition is basically finished by our circuit.