Design Of High Performance Trigger System For 40GSPS Oscilloscope

With the rapid development of electronic information technology,the requirements for electronic measuring instruments are also increasing.As an important instrument in the field of time-domain test,the oscilloscope has more and more complex electrical signals and more special waveforms.The function of ordinary oscilloscope is not enough to meet the needs of users.In order to ensure the stable triggering of the waveform and make the stable display of the waveform easy to observe or capture the waveform of interest to the user,the trigger system is an indispensable part of the oscilloscope.40 GSPS digital oscilloscope also puts forward higher requirements for the trigger system performance.This paper is devoted to the research and design of the trigger system of 40 gsps digital oscilloscope,and improves the performance of the trigger system by using high-speed deserializer and digital trigger technology.The main contents of this paper are as follows:1?Edge triggering technology based on pure digital circuits.Starting from the trigger principle of the oscilloscope,combined with the analysis of the principle and limitations of the analog edge trigger of the oscilloscope,a pure digital trigger system with software and hardware coordination is designed for the 40 GSPS digital oscilloscope.By directly using the digital signal sampled by the ADC as the trigger source.After the sampled parallel digital signal passes through the digital comparison module and the trigger module,the parallel trigger signal that generates multiple data is transmitted to the processing board through the acquisition board to generate precise positioning information of the actual trigger point to control the FIFO storage and make the oscilloscope display stable capture waveforms to achieve full bandwidth trigger.2?High precision digital advanced trigger system.Aiming at the original advanced trigger mode of oscilloscope,the trigger instability of acquisition of abnormal signal is studied.Because the sampling rate of 40 GSPS digital oscilloscope is higher than that of traditional oscilloscope before,it also puts forward higher requirements for acquisition of abnormal sensitive signal.Therefore,a high-precision advanced trigger mode is proposed,which greatly improves the trigger limit parameters of the advanced trigger mode,and improves the trigger precision from nanosecond level to picosecond level.3?Based on the design of trigger module of GTX receiver in FPGA,the digital signal after the disconnection corresponds to the ADC sampling data one by one with the data of GTX receiver to realize precise trigger.It mainly includes the debugging of GTX serial port to make it receive and de string data accurately and the design of trigger module.The trigger based on GTX de string device is applied to 40 GSPS Digital Oscilloscope by triggering the ADC sampling data buffer control enable and combining with the software processing of the waveform data sent and displayed.Relying on the 40 GSPS oscilloscope platform,a complete set of high-performance trigger system is designed,which digitizes the trigger system,so as to improve the accuracy of different trigger modes and enable the oscilloscope to achieve accurate trigger.After the application of the high performance trigger system,the result shows that the system can make the oscilloscope trigger stably,realize the real-time trigger location and capture the instantaneous signal.The function performance of the whole trigger system has been improved.