Research on the High-Speed Data Acquisition System Based on Clock Distribution

Abstract

In order to digitize the signal of high frequency or ultra-high frequency, clock distribution technology with the same frequency but different phase is utilized as a solution to this difficulty. The principles of high-speed analog-to-digit converter (ADC) by the lower rate ADC module, key technology and key module of the data acquisition systems are studied. From the aspects of system architecture, clock distribution module based on the AD9520, ADC module based on the AD9480 and data processing, the design method of ultra-high-speed ADC by clock distribution mode are explored. The results show that: driving many ADC modules with serial clocks of the same frequency but different phase in parallel to sample the same signal, the sampling frequency of the ADC system is the sum of each ADC sampling frequency. Four AD9480 modules are driven by four-way 250MHz clocks with phase fault 90°, respectively. And 1GHz samples per second can be attained, which is four times of the sampling frequency by monolithic AD9480.