【摘要】 基于4片5GS/s的TIADC结构设计了20 GS/s高速数据采集系统,将之应用于数字示波器上。采用4片FPGA接收和存储采样数据的架构降低了系统成本,对多FPGA之间数据存储的同步问题进行了分析,并提出了基于TDC的同步解决方案;提出了基于正弦拟合的TIADC误差校准算法,校准前后信号频谱的对比证明了校准算法有效性。实验结果表明,系统实现了20 GS/s的采样率。在输入500 MHz正弦信号时,系统的SNR为40.376 dB,ENOB为6.446 b,2.5 GHz正弦输入时ENOB仍然有6.085 b,给出了系统ENOB随频率变化曲线。实验数据表明系统技术指标处于国内领先水平。更多还原

【Abstract】 A 20 GS /s high speed data acquisition system is designed based on four 5 GS /s TIADC,and is applied in DSO. The architecture of using four FPGAs to receive and store sample data cuts down the system cost. The synchronization problem of the data storage among multiple FPGAs is analyzed,and a synchronization scheme based on TDC is suggested to solve the problem. The TIADC error calibration algorithm based on sine-fitting is proposed; and the comparison of the signal spectrums before and after calibration proves the effectiveness of the calibration algorithm. The experiment result shows that the system realizes 20 GS / s sample rate; the SNR is 40. 376 dB,ENOB is 6. 446 b when a 500 MHz sinewave signal is inputted; and the ENOB is 6. 085 b even when a 2. 5 GHz sinewave signal is inputted. The curve of system ENOB versus frequency is given. The experiment data show that the technical specifications of this system are at domestic leading level.更多还原