| Digital storage oscilloscope has many advantages compared with analogue oscilloscope, such as the single signals capturing, waveform storage and replaying, self testing, etc. So digital storage oscilloscope is widely used and promoted in the electronic field. In many cases oscilloscope needs to test many signals which are not allowed to have same ground. Using ordinary oscilloscope may get wrong results or damage experiment circuit.This paper studied the sampling way of digital storage oscilloscope and the data acquisition algorithm of real-time sampling. The oscilloscope in this paper uses DSP and CPLD hardware structure and has four isolated acquisition channels. This paper introduces signal regulate circuit, trigger circuit, AD converter circuit and liquid crystal display circuit. DSP is the master of the whole hardware structure which control the whole system and data acquisition. CPLD manage peripheral circuit and drive LCD display.Attenuation network uses relays to choose different combination of resistance to fade signal detected. The isolated acquisition channels use CIM1100 which is MHz level broadband amplifier to realize isolating between them. MAX1180 is the AD converter in of the digital storage oscilloscope. This design adopted LCD as screen displayer and designed the display driver which produces various timings and formulates corresponding control commands. The digital storage oscilloscope uses LCD to display signal waveform.The software design uses modular designing which makes every module independ (?)t among each other and software upgrading simple. The linear interpolation and the sine interpolation algorithm is applied in the real-time sampling which also is realized in software programming.The test proofed that the digital storage oscilloscope this paper introduced can accurately and clearly display signal waveform. Also this digital storage oscilloscope has good isolated effects which can achieve the performance requirements in the practical application. |
