.40 Gsps Random Sampling Digital Oscilloscope Key Technologies Advance Research

The thesis task is a part of the project of 500MHz random sampling wideband digital storage oscilloscope. The oscilloscope's real time sampling is up to 500Msps, and equivalent sampling up to 40Gsps.High-speed random sampling of high-speed DSO (Digitizing Storage Oscilloscope) is discussed in this thesis and which is mainly analyzed in the time-domain. We also discuss the design of dedicated LCD (Liquid Crystal Display) controller for DSO and how to display the channel signal on the LCD.Based on the principle of random sampling of DSO in the time-domain, two ways ("time amplifying in dual slope integral" and "time–voltage convert") are implemented to measure the time between the system trigger and writing clock. Thus random sampling interpolate can be done to measure repeated signal in high frequency with the A/D converter and controller whose frequency are lower. In this chapter, circuits of these two ways are also concerned. With the experiments' help, the circuit is improved for advanced research.In the LCD controller design, the scan signal and data signal of LCD needed are provided by DSP (Digital Signal Processor). The DSP also deal with the display data transmitted from primary CPU, such as the vector display of channel signal, Fast Fourier Transform (FFT) applied to it and so on. This controller can improve the performance of DSO in the display greatly.At last we also discussed the guidelines of high-speed board layout and the characteristic impedance's calculation of the circuit trace on the PCB.