Design Of FPGA Based Auto-gated Power Supply Circuit For Image Intensifier

The low-light-level (LLL) image intensifier (I~2) which can detect two dimensional weak light picture is mainly used to observe targets in the battlefield during the night time. Because light level of field of view changes much in the battlefield, I~2 must have a wide dynamic range of all-weather battle. The dynamic range and lifetime of GenerationⅢ, it is not big enough. The target of this thesis is to overcome these disadvantages by an auto-gated Power supply.The paper mainly introduces the auto-gated power supply of low-light-level image intensifier, and analyzed its structure and working principle in detail. Design high voltage power supply for the auto-gated power supply.Design an ADC for low frequency of measurement. The part can accept low level input signals directly from a transducer and outputs a serial digital word. It employs a Sigma-Delta conversion technique to realize up to 8 bits of no missing codes performance. The input signal is applied to a proprietary programmable gain front end based around an analog modulator. The modulator output is processed by an on-chip digital filter. The first notch of this digital filter can be programmed via the on-chip control register allowing adjustment of the filter cutoff and output update rate.Introducing a circuit scheme of digital high frequency pulse width modulator based on the FPGA. The structure and working principle of the circuit are analyzed in detail. The simulative and experimental results show that the circuit is accurate and practical.