Research And Design Of Multi-channel Digital-analog Hybrid Acquisition And Storage Device Based On CML

With the gradual development of military, aviation and aerospace industry, more and more information need to be collected, measured and recorded and the speed is required to increase during flight tests or practical applications of launch vehicle, missiles and other weapons. The information includes the environmental load capacity and high speed digital quantity. In view of the current status and requirements, a multi-channel digital-analog hybrid acquisition and storage device based on CML is proposed.According the modular design method, this device is divided into four modules to design,including power module, digital and control module, analog conditioning module, and data recording module. This method makes it convenient to modify and maintenance the whole device. The main research contents can be divided into the following four sections. Firstly, the power-supply module design is optimized. The principle of electromagnetic interference and filtering theory of filter circuit consisting of corresponding independent elements are described. The EMI filter circuit is developed based on the electromagnetic filter module.Simultaneously, the working principle on equivalent inductance in PCB electrical wire is analyzed and the corresponding methods are considered to avoid this effect. In addition, in view of the requirement of several isolation powers in this device, the influence of excessive filter capacitance on the power is considered and analyzed. Secondly, CML interface technology is selected for image data receiving of the seeker. In this section, the principle and structure of CML interface is introduced. The TLK1501 of TI is selected as interface chip and the feasibility of data receiving at 1.5Gbps transmission rate is verified. Furthermore, the interface circuit is designed and the feasibility is increased by designing the decelerating,isolating and adopting shield twisted-pair cables. Thirdly, acquisition conditioning circuit of electric charge output sensor is designed. In view of induced charge interference from electromagnetic induction and electrostatic discharge during the transmission electric charge,the interference mechanism is described in detail and corresponding solution is proposed.Fourthly, the FPGA control logic was designed, which is divided into several modules to achieve logic controlling of each transmission interface, mixed framing, data transmission,data read back and control. Moreover, data cache is designed by utilizing internal RAM.Finally, device test platform is built to form a closed-loop test system so that the device’s each function is characterized and the performance is verified successfully. The device successfully has been successfully applied to a missile-borne test system.