Design Of High-speed Arbitrary Waveform Generator Circuit

In modern test systems, the need to use the signal source is inevitable. Thetraditional function signal generator has a simple, flexible features, but usually has tlow output signal frequency, and the types of signals is few, not convenient enoughto regulating. With the development of technology, digital signal generator with itsflexible for configuration, a variety of signal output capability anduser-programmable features are more and more popular. However, due torestrictions of the device level, the sampling rates of the digital signal generator isusual not high enough, so how to improve the sampling frequency of the signalgenerator as much as possible under the existing conditions is the focus of currentlywork.In this paper, FPGA is used to achieved high-speed interface with DACdevices,which used internal resources in FPGA realsizing parallel to serialconversion. The internal FPGA memory resources is also used to achieve storagesystem, thereby reducing the pressure on the peripheral circuit layout and achieve abetter performance in the two-way arbitrary waveform generator design. The designalso include two-way output synchronous circuit, as well as the correspondinganalog circuit, which provide an other choice of the DAC output between op ampand transformer, the test results show that the system meets the target. The systemalso uses a USB interface to communicate with the host computer which usingMatlab generate user-defined waveforms, the peripheral circuit control systems areimplemented within the FPGA,too.The implemente take full advantage of FPGAresources to realized the multiple sources synchronization and associated interfacecircuit design. For later development needs, the design provides interfaces for Flashmemory expansion, as well as other functional.As this is a designed for high-speed digital-analog hybrid circuit, so thehigh-speed circuit design issues that need attention are analyzed, and also the filterlayout and pcb layout were introduced.In the last of the paper,the test results andproblems in the testing is given,which provided experiences for deeper research.