Test Technology Of High-speed And High-resolution D/A Converter

D/A Converter(Digital to Analog Conver), which is called DAC for short, is a device that converts digital codes to an analog signal. DAC is a bridge between the digital signal processing in the computer and the real world’s signal. It is widely used in the fields of the modern electronic designs. With the continuous improvement of the performance of the DAC, high-speed and high-resulotion DAC applications in radar, electronic warfare, communications, instrumentation and other areas is also increasing in depth. So, request to test and evaluate of the high-speed and high-resulotion DAC in the engineering applications is increased day by day.As a typical mixed signal devices, Testing and evaluating the DAC is different from the analog devices, but also from digital devices, more than simpy equal to the sum of the two above. It requires great skills and rich debugging experience, including signal conditioning, signal filtering and amplifying, in the analog test area, and also requires the high-speed digital test skills, including data capture, sequence and timing matching and digital signal processing. It requires two signals simultaneously stimulate and measure, but also requires a fairly high degree of isolation between to avoid interference. Therefore, testing and evaluating DAC has considerable challenge.In this paper, we first conduct research on the DAC’s mathematial model, the basic structures, the test methods, and the key technologies for high-speed test and highresulotion test, repectively. Then, a design of an automatic test system is introduced, which is low cost and suitable for evaluate the high-speed and high-resulotion DAC’s static and dynamic performance. From the test results, the test system has high accuracy, and is very fit for the fast performance evaluation to DAC in engineering applications. Research contents are as follows:1) Conducted an investigation on the development status of the DAC’s test methods. Introduced the test methods of the DAC used in the major converter design companys.2) Analyzed for the DAC’s mathematial model and basic structures. On this basis, give the test precautions for the different DAC’s structures.3) Depth study on the DAC’s common electrical parameters, Include the definition, the algorithm, and the theory. Combined with the DAC’s different structures, it could enhance the test accuracy and test speed.4) A research on the strucure of the DAC’s test system. Then designed a test system suitable for the DAC’s performance evaluation in the laboratory. In this system, a digital pattern generator and a evaluation board was also designed. Finally, a 14 bits 2.5GSPS sample rate DAC was tested in this system, and got the test results with expectations.