Design and development for power supply circuit of a low-light detection imaging system

The low-light detection remote sensing system is capable of imaging at night and in the morning and evening, which can effectively make up for the shortcomings of conventional satellite dynamic monitoring capability. It can improve China's emergency response speed to major natural disasters and major events, and effectively increase the depth and breadth of the application of earth observation technology in the field of disaster prevention and mitigation. In a pre-project about low-light detection principle prototype development, the Image Intensifier coupled CCD sensor (ICCD) is used as the core imaging device of the low-light detection system, the entire system consists four parts such as a detector ICCD module, the main control and processing unit FPGA module, signal processing circuits and power supply module . Among them, the power supply is used to provide low-noise power for the other three modules. The main control pulse which comes from FPGA of master control processing unit, can drive the detector ICCD. And then the ICCD will get low-light radiation through the optical system and finish photoelectric conversion. Ultimately the low-light detection system can output high-speed digital image signal data. On the basis of fully analyzing the input power ripple, electromagnetic interference generated by the layout and wiring of power supply PCB components and thermal noise generated by heat dissipation on the imaging performance of the low-light detection system, this paper designs a power supply circuit system which combined several DC/DC modules and a variety of LDOs (low-voltage differential voltage regulators). Starting from the selection of components, PCB layout and wiring, power-up sequence design, etc. The single power supply of the satellite platform is converted into 10 kinds of power supply circuits with different load currents, functions and performance requirements, such as +18V, +13.5V, +12V,+11V, +8V, +7V, +5V, +3.3V, +1.5V and -7V. After single-board debugging and system testing, the output ripple of each power supply is measured to be no more than 20mV, low noise, high stability and anti-jamming , which meets the design objectives of the power supply circuit. Ultimately the entire low-light detection system obtain high-quality low-light images in the outdoor low-light conditions.