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The uncooled infrared detector is the core of the uncooled infrared camera. As the connection part of infrared detector and signal processing system, the performance of the focal plane circuit directly restricts the final imaging quality of the camera. According to the characteristics of power supply and temperature control of space-borne 640×512 uncooled infrared detector, a focal plane circuit is designed, which consists of a detector power supply circuit, a detector temperature feedback circuit and a detector temperature control circuit. In the detector power supply circuit, the bias generation circuit composed of DCDC, LDO and operational amplifier is designed for the characteristics of the 640×512 uncooled infrared detector with many kinds of bias and high precision. According to the working requirements of the temperature measuring diode of 640×512 uncooled infrared detector, a 1mA constant current circuit is designed to generate 1mA constant current, and a voltage conditioning circuit is responsible for detecting the voltage value of the temperature measuring diode. In the temperature control circuit of detector, the temperature control system of uncooled infrared detector based on temperature control chip is designed. The system can realize the closed-loop automatic control of thermoelectric cooler (TEC), which has the advantages of low power consumption, high precision and high reliability. The experimental results show that the system can effectively control the temperature of infrared detector at room temperature. When the operating temperature of the detector is -10°C, the accuracy can reach 0.07°C, which meets the requirements of the detector in orbit. After introducing the design method and design idea of each component of focal plane circuit in detail, the designed circuit is tested. The test results show that the design scheme is correct and feasible, and meets the design requirements of the focal plane circuit of the uncooled infrared camera.
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