Design And Implementation Of The High-Speed ADC Test Platform

Analog to digital converter (ADC) is an important part of the communication system, it has a very important significance for the development of the communication system. With the demand for high frequency, high-bandwidth and multi-mode communication in the communication system, ADC is promoted to the direction of high-speed and high-accuracy, it greatly increases the difficulty of ADC’s design and testing. Due to the arrangement, voltage, agreement of the ADC’s pin is diverse and ADC has a large number of performance indicators, the design of a common ADC test platform is of great significance to the development and production of the ADC chip.This paper designs and implements an ADC test platform with the toppest speed of 250 MSps and the highest accuracy of 14 bit. Firstly, system implementation is determined on the basis of research, the ADC test platform from the system is devided into high-speed signal processing module, controlling and communication module and software module three parts. For that ADC works in a high speed, the arrangement, voltage, agreement of the ADC’s pin is diverse, ADC’s performance indicators are needed to be computed and so on, FPGA chip of Xilinx’s Virtex-6 series is selected to constitute high-speed signal processing module. The use of FPGA that operates in a high frequency, has abundant resources, is stongly programmable and occupies other characteristics, by calling IBUFGDS, IDDR, RAM, CLK IP core logic and other resources, achieves receiving, processing and storaging the output signal of the high-speed ADC. Controlling and communication module selects ARM running the Linux operating system, it fully plays features that ARM has strong controlling ability and open source Linux operating system can be customized and has strong portability to control the ADC hardware platform and use Fast Ethernet to transmiss ADC sampling data to the PC. NI’s LabWindows/CVI software is selected as a development platform of the software module on the PC, software is customized with rich functions according to the needs of high-speed ADC test platform. Facilitate and friendly interface is designed to make general testers test ADC’s SINAD, SNR, SFDR, THD and other performance parameters easily, and it also provides professionals a channel to configure and test ADC chip internal registers.Finally, the high-speed ADC test platform takes an ADC chip ADS58C23 as a testing object, the test is under the sampling clock of 250MSps. Under the case that input signal frequency is 170.5MHz and signal amplitude is-1dBFS, the results show the measured SINAD is 68.4dBFS, SNR is 68.5dBFS, SFDR is 82.2dBc, THD is 82.0dBc, testing results meet ADS58C23 data sheet performance.