高速高精度ADC动态参数评估系统的设计与实现

Design and Implementation of Dynamic Parameter Testing System for High-speed and High-precision ADCs

摘要:

高速高精度模数转换器(ADC)广泛应用于信号处理领域,其动态性能直接决定系统性能的优劣；由于实际使用的芯片与设计的额定指标间会存在偏差,有必要评估ADC的实际动态性能；基于FPGA及Labview实现了一个低成本、高可靠性的高速高精度ADC性能评估系统；系统由底层控制待评估ADC子卡,提供精确的采样样本；采用异步FIFO进行数据缓存, DMA方式优化数据存储；Labview定义通信模块,结合Matlab测试脚本完成动态参数测试；最后使用ADI公司的AD9467进行了测试验证；实验结果表明,该系统运行稳定,与datasheet相比,参数误差不超过1.89%,达到了IEEE Std 1241-2000的测试标准,降低了测试系统构建难度和成本。

Abstract:

High-speed and high-precision analog-to-digital converters (ADCs) have been widely used in signal processing,their dynamic characteristics directly determine the system performance.Since there always exist deviations between practical chip parameters and designed indices, it is necessary to evaluate the actual dynamic performance of ADCs. By building an ADC hardware and software test platform based on FPGA and Labview, a low cost and high reliability performance evaluation system is constructed for high-speed and high-precision ADCs.The system controls the sub-ADC in bottom layer to provide accurate sampling; Asynchronous FIFO is used to carry out data cache, and DMA method to optimize data storage; Labview defines the communication module, combined with Matlab’s scripts to test the dynamic parameters.Finally, AD9467, a high-speed and high-precision ADC of ADI, is used for verifying the implemented system. Experimental results show that the system works stably, and the errors are within 2% compared with datasheet, which reaches the test standard provided by IEEE Std. 1241-2000, and the difficulties and cost in constructing the evolution system can be reduced.