High-trigger-accuracy oscilloscope

Abstract

The invention provides a high-trigger-accuracy oscilloscope. The high-trigger-accuracy oscilloscope comprises: a setting unit for setting comparison levels; a data sampling unit for performing digital sampling on a tested signal to obtain n sampled data, wherein n is greater than or equal to 1; a numeric comparison unit for performing the level comparison process on each sampled data separately according to a first high level and a first low level to generate n first comparison signals and performing the level comparison process on each sampled data separately according to a second high level and a second low level to generate n second comparison signals, wherein the first high level is less than or equal to the second low level; and a trigger control unit for performing the trigger logical process according to the comparison signals to generate a trigger signal. According to the invention, the level comparison process is performed on the sampled data through four comparison levels, so not only the noise can be eliminated, and but also the time error can be reduced, so that the trigger position which is expected by a user is more close to the trigger position which is generated actually, so the trigger accuracy can be improved.

Description

technical field [0001] The invention relates to the technical field of test and measurement, in particular to an oscilloscope with high trigger precision. Background technique [0002] Oscilloscope is an electronic measuring instrument with a wide range of uses. It can convert electrical signals invisible to human eyes into waveform images visible to human eyes, which is convenient for people to study the changing process of various electrical signals. Digital storage oscilloscopes (DSO), referred to as digital oscilloscopes, convert the measured signal into digital information through an analog-to-digital converter and store it, and use the stored data to reconstruct the waveform signal and display it on the screen of the oscilloscope. [0003] Triggering is one of the core functions of the oscilloscope. The so-called triggering refers to setting certain triggering conditions according to requirements. When the waveform in the signal under test meets the trigger condition,...

AI Technical Summary

Problems solved by technology

[0009] The above method of using the viscous comparator to form the digital comparison unit 202 successfully eliminates the interference caused by the noise v in the measured signal, so that the comparison signal c1 does not fluctuate, and avoids the problem of false triggering caused by noise. However, when comparing the two comparison levels of the sticky comparator to generate the comparison signal c1, there is a time delay t related to the sticky level at its rising and falling edges, such as figure 2 As shown, compared with the comparison signal c2 expected by the user, there is a certain error t between the two. Therefore, this method inevitably has the problem of inaccurate trigger position

For example, when the user expects the pulse width of the comparison signal to be T2, the trigger will be generated, but the actual pulse width of the comparison signal is T1, and the trigger cannot be generated here

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