Method for automatically calibrating direct current accuracy of digital oscilloscope on basis of binary search

Abstract

The invention discloses a method for automatically calibrating the direct current accuracy of a digital oscilloscope on the basis of the binary search. After the method is adopted, the aims of reducing the calibrating time of the digital oscilloscope and improving the calibrating accuracy can be fulfilled. Specifically, the method comprises the following steps: a user sets a corrected value of anadder of a front-end conditioning circuit, a channel and a range of the digital oscilloscope, a calibration error limit epsilon and a voltage amplitude Dexp of a calibration target analog voltage signal; when the corrected value of the adder is set into Vmin, the digital oscilloscope starts to acquire to obtain an average value Dmin corresponding to the Vmin; likewise, the corrected value of the adder is set into Vmax, an average value Dmax corresponding to the Vmax is obtained; an upper computer carries out data processing by adopting a binary search algorithm and generates a calibrating result Vexp according to the Dmin, the Dmax, the Dexp and the epsilon; the upper computer sends the Vexp to a storage and resets the digital oscilloscope; and when the user restarts the upper computer, the upper computer reads the calibrating result from the storage and writes the calibrating result into the adder in the front-end conditioning circuit, wherein the calibrating result is used for correcting a direct current error generated by the front-end conditioning circuit.

Description

technical field [0001] The invention belongs to the field of digital oscilloscopes, and in particular relates to an automatic calibration method for DC precision of a digital oscilloscope based on a half-search. Background technique [0002] Since Nicolette Corporation of the United States successfully developed the world's first digital oscilloscope in 1972, after years of development, it has been widely used in various industries. Its working principle is that the input signal is controlled by the time base circuit, samples are taken at a certain time interval, and then quantized by the A / D converter to transform these instantaneous values ​​or sampled values. Due to the different hardware circuit characteristics of each digital oscilloscope, after the signal is conditioned by the front-end conditioning circuit of the oscilloscope, a DC error with an uncertain amplitude will be introduced, which requires an addition circuit in the front-end conditioning circuit to correct ...

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Problems solved by technology

[0003] However, in the actual calibration process, the designer usually obtains the correction value of the adder through a step-by-step method based on his own experience, which will consume a lot of manpower and time

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